Well, it's Tuesday, and you all know what that means... IBM announcements!
This week, IBM announced the IBM Tivoli Storage Productivity Center for Disk Midrange Edition, affectionately referred to as "MRE". This is basically TPC for Disk but with two key differences:
- A special license that covers only DS3000, DS4000, DS5000 series, whether natively attached or virtualized behind SAN Volume Controller.
- A new pricing model based on the number on controllers and drawers, rather than by TB managed. For example, if you have a DS5300 and two expansion drawers, then you pay for three units of MRE. As you upgrade from smaller capacity disks to larger capacity disks, your license costs won't increase. This eliminates the quarterly hassle to "true up" your software licenses to match actual capacity that is required on TB-based licensing.
This includes the [new DS3500 model] that was announced last month. This was part of the set of solutions to [help midsized businesses].
A fresh new blogger on the scene, Anthony Vandewerdt (IBM), covers [10 things I like about the IBM DS3500], saving me the trouble.
For more information on Tivoli Storage Productivity Center for Disk Midrange Edition, see the IBM [Announcement Letter].
technorati tags: IBM, Tivoli, Productivity Center, Midrange+Edition, MRE, TPC, DS3000, DS3500, DS4000, DS5000, Anthony Vandewerdt
Did IBM XIV force EMC's hand to announce VMAXe? Let's take a stroll down memory lane.
In 2008, IBM XIV showed the world that it could ship a Tier-1, high-end, enterprise-class system using commodity parts. Technically, prior to its acquisition by IBM, the XIV team had boxes out in production since 2005. EMC incorrectly argued this announcement meant the death of the IBM DS8000. Just because EMC was unable to figure out how to have more than one high-end disk product, doesn't mean IBM or other storage vendors were equally challenged. Both IBM XIV and DS8000 are Tier-1, high-end, enterprise-class storage systems, as are the IBM N series N7900 and the IBM Scale-Out Network Attached Storage (SONAS).
In April 2009, EMC followed IBM's lead with their own V-Max system, based on Symmetrix Engenuity code, but on commodity x86 processors. Nobody at EMC suggested that the V-Max meant the death of their other Symmetrix box, the DMX-4, which means that EMC proved to themselves that a storage vendor could offer multiple high-end disk systems. Hitachi Data Systems (HDS) would later offer the VSP, which also includes some commodity hardware as well.
In July 2009, analysts at International Technology Group published their TCO findings that IBM XIV was 63 percent less expensive than EMC V-Max, in a whitepaper titled [COST/BENEFIT CASE
FOR IBM XIV STORAGE SYSTEM Comparing Costs for IBM XIV and EMC V-Max Systems]. Not surprisingly, EMC cried foul, feeling that EMC V-Max had not yet been successful in the field, it was too soon to compare newly minted EMC gear with a mature product like XIV that had been in production accounts for several years. Big companies like to wait for "Generation 1" of any new product to mature a bit before they purchase.
To compete against IBM XIV's very low TCO, EMC was forced to either deeply discount their Symmetrix, or counter-offer with lower-cost CLARiiON, their midrange disk offering. An ex-EMCer that now works for IBM on the XIV sales team put it in EMC terms -- "the IBM XIV provides a Symmetrix-like product at CLARiiON-like prices."
(Note: Somewhere in 2010, EMC dropped the hyphen, changing the name from V-Max to VMAX. I didn't see this formally announced anywhere, but it seems that the new spelling is the officially correct usage. A common marketing rule is that you should only rename failed products, so perhaps dropping the hyphen was EMC's way of preventing people from searching older reviews of the V-Max product.)
This month, IBM introduced the IBM XIV Gen3 model 114. The analysts at ITG updated their analysis, as there are now more customers that have either or both products, to provide a more thorough comparison. Their latest whitepaper, titled [Cost/Benefit Case for IBM XIV Systems: Comparing Cost
Structures for IBM XIV and EMC VMAX Systems], shows that IBM maintains its substantial cost savings advantage, representing 69 percent less Total Cost of Ownership (TCO) than EMC, on average, over the course of three years.
In response, EMC announced its new VMAXe, following the naming convention EMC established for VNX and VNXe. Customers cannot upgrade VNXe to VNX, nor VMAXe to VMAX, so at least EMC was consistent in that regard. Like the IBM XIV and XIV Gen3, the new EMC VMAXe eliminated "unnecessary distractions" like CKD volumes and FICON attachment needed for the IBM z/OS operating system on IBM System z mainframes. Fellow blogger Barry Burke from EMC explains everything about the VMAXe in his blog post [a big thing in a small package].
So, you have to wonder, did IBM XIV force EMC's hand into offering this new VMAXe storage unit? Surely, EMC sales reps will continue to lead with the more profitable DMX-4 or VMAX, and then only offer the VMAXe when the prospective customer mentions that the IBM XIV Gen3 is 69 percent less expensive. I haven't seen any list or street prices for the VMAXe yet, but I suspect it is less expensive than VMAX, on a dollar-per-GB basis, so that EMC will not have to discount it as much to compete against IBM.
technorati tags: IBM, XIV, Gen3, EMC, DMX-4, VMAX, V-Max, HDS, N7900, SONAS, DS8000, CKD, FICON, TCO
I gotten several emails expressing worry that I have fallen off the face of th earth. The last two weeks have been educational and eye-opening for me. I can't provide details in my blog, so I will just say that it involved government agencies that IBM refers to as "dark accounts", and that I am now back safely in the USA. Between adjusting to time zone differences, ridiculously long hours, and restricted access to the internet, I was unable to blog lately.
Instead, I will resume my coverage of the [IBM System Storage Technical University 2011]. The "Solutions Expo" runs Monday evening through Wednesday lunch. This is a chance for people to explore all the solutions that are part of IBM's large "eco-system" for IBM System storage and System x products. There were several sponsors for this event.
As is often the case at these conferences, the various booths hand out fun items. The hot items this year were tie-dyed tee-shirts from Qlogic, and propeller beanies from the IBM rack and power systems team. Here is Amanda, one of the bartenders showing off the latter.
After the expo on Tuesday night, my friends at [Texas Memory Systems] held an after-party. Unlike the pens, tee-shirts and keychains at the Expo, these guys had a raffle for real storage products. Here is Erik Eyberg handing out a RamSan PCIe card, valued at $14,000 or so. IBM recently certified the TMS RamSan as External SSD storage for the IBM SAN Volume Controller (SVC). The SVC can optimize performance using this for automated sub-LUN tiering with the IBM System Storage Easy Tier feature.
technorati tags: IBM, Storage, University, Qlogic, TMS, RamSan, SVC, Easy Tier
Modified by TonyPearson
Well, it's Tuesday again, and you know what that means? IBM announcements!
Today's announcements are all about the Storwize family, IBM's market-leading Software Defined Storage offerings. Having sold over 55,000 systems, and managing over 1.6 Exabytes of data, IBM continues to be the #1 leader in storage virtualization solutions. The Storwize family consists of the SAN Volume Controller (SVC), Storwize V7000, Storwize V7000 Unified, Flex System V7000, Storwize V5000, Storwize V3700 and V3500.
SAN Volume Controller 2145-DH8
The new 2145-DH8 model is a complete repackaging of this popular storage system. The previous model, the 2145-CG8, was 1U-high x86 server per node, and each node required a separate 1U-high UPS to provide battery protection for its cache. Nobody liked this. The new 2145-DH8 instead is a 2U-high node with two hot-swappable batteries, eliminating the need for UPS altogether. Thus, an SVC node-pair using the 2145-DH8 models takes up the same 4U space, but with fewer cables. The SVC can now also support standard office 110/240 voltage sources.
The new model sports an 8-core processor with 32GB RAM. Since these are 2-socket servers, IBM offers that option to add a second 8-core processor and additional 32GB RAM to help boost Real-time Compression. Each node can have optionally one or two hardware-assisted compression cards which use the Intel QuickAssist chip to boost compression performance.
While the Real-time Compression was in fact, real-time, performed in-line to the read/write I/O process, at latency comparable to uncompressed data for applications, the compression process on older models was entirely software-based, consuming some of the CPU resources, which lowered the maximum IOPS of the solution. With the added cores, added RAM, and hardware-assisted compression chips, IBM resolves that concern. In fact, the new 2145-DH8 with compression can provide more IOPS than an older 2145-CG8 without compression.
The previous model 2145-CG8 allowed you to put up to 4 small SSD drives in the node itself, which were treated the same as externally Flash drives for purposes of having a high-speed storage pool for select volumes, or automated sub-LUN tiering with Easy Tier. The new model 2145-DH8 allows you to attach up to 48 Solid State Drives (SSD) via 12Gb SAS cables. These are housed in the new 2U-high 24F enclosures that can offer up to 38.4 TB of Flash per SVC I/O group.
IBM also re-designed the host/device ports to use Hardware Interface Card (HIC) slots. In the 2145-CG8, you had four FCP ports, two 1GbE Ethernet ports, with options to add two 10GbE Ethernet ports or four additional FCP ports. If you had mostly an FCoE or iSCSI environment, you didn't need the FCP, and if you were mostly a FCP Storage Area Network (SAN) environment, then most of the Ethernet ports went unused. To solve this, the 2145-DH8 can allow you to have up to six HIC cards that are either FCP, Ethernet, or SAS. There are three 1GbE fixed Ethernet ports which can be used for iSCSI and administration.
If you have SVC today, you can upgrade non-disruptively by either swapping out your current SVC engines with the new 2145-DH8 engines, or you can add the new 2145-DH8 engines to your existing SVC cluster. Either way, there is no outage to your applications!
To learn more, see the [Announcement letter: SAN Volume Controller Storage Engine DH8].
New Storwize V7000 hardware
This is the next generation of the popular Storwize V7000. The previous generation had a 4-core processor and 8GB RAM per canister. The new model has an 8-core processor with 32GB of RAM per canister, with the option to double these to boost Real-time compression. There are two canisters per control enclosure, which gives you 64GB to 128GB of RAM per Storwize V7000 I/O group.
The new Storwize V7000 comes with one hardware-assisted compression chip on the mother board of each canister, with the option to add a second chip per canister.
Each canister offers three HIC slots, which can be used for the additional hardware-assist compression chip, FCP or Ethernet ports.
To accommodate these HIC slots, new canisters were needed. Instead of the flat wide style top and bottom, we now have taller, thinner canisters that sit side to side. This side-to-side design is similar to our existing Storwize V5000 and V3700 models.
The previous model could support up to 9 expansion enclosures per control enclosure. The Storwize V7000 can have up to 24 drives in its control enclosure, and now attach up to 20 expansion enclosures, which allows up to 504 drives per control enclosure, and up to a maximum of 1,056 drives per Storwize cluster.
If you have previous models of Storwize V7000, you can add the new Storwize V7000 into the same cluster, or virtualize the previous storage for migration purposes.
To learn more, see the [Announcement letter: New Storwize V7000].
IBM Storwize Family Software V7.3.0
The new software applies new capabilities to both new generation hardware as well as the older models, so people with existing gear can benefit as well.
In prior releases, the sub-LUN automated tiering was limited to two levels: Flash and HDD. This lumped all 15K, 10K and 7200 RPM drives into a common HDD category. In the new v7.3.0 code, you can now have three levels: Flash, Enterprise HDD, and Nearline HDD, or two HDD levels: Enterprise and Nearline. The Enterprise level combines 15K and 10K RPM drives, similar to what is done on the IBM System Storage DS8000 disk systems.
The new code is also able balance your storage pools, and can be used with uniform or mixed storage pools to eliminate performance hot spots.
The new code has been enhanced to detect the hardware-assisted compression chip on the new SVC and Storwize V7000 models, and use those if available.
For the Storwize V3700 and V5000 models, the new code allows up to nine expansion enclosures per control enclosure. In the previous models, the V3700 allowed only four expansions, and the V6000 only six expansions per control enclosure. The V3700 can now support up to 240 drives, and the V5000 can support up to 480 drives.
To learn more, see the [Announcement letter: Storwize Family Software v7.3.0].
IBM Storwize V7000 Unified File Module software v1.5
For Storwize V7000 Unified clients, there is new software for the File Modules that provide NFS, CIFS, FTP, HTTPS and SCP protocol capability. The new v1.5 code now adds NFS v4 and SMB 2.1 levels of support. Most NFS users are still on NFSv3, but about 20 percent of NFS users are using NFS v4 which offers stateful access. The SMB 2.1 for CIFS was introduced by Microsoft in Windows 7 and Windows Server 2008 R2.
Deterministic ID mapping allows you to map Windows userids to UNIX/Linux group and owner id numbers. In the past, the problem is that this mapping is different on each machine, so people often had to stand up a Windows System for Unix Services (SFU) server to provide consistent ID mapping. Now, with v1.5 code, you will no longer have to do this. The deterministic ID mapping will can now replicate the mapping to each machine without an SFU server.
Active Cloud Engine allows up to ten Storwize V7000 Unified to be connected across distance to form a single global name space. WAN caching, however, was restricted to a single site having write capabilities, while the others were read-only. In v1.5 release, IBM now supports multiple independent writers at different locations on the same fileset.
Security enhancements include multi-tenancy, configurable password policies, session policies, and hardened boot and SSH configurations. With NFS v3/v4, you can now use [Kerberos] for security.
Finally, I am please to see that we now have Cinder support for files on the Storwize V7000 Unified on the OpenStack Havana release that just came out last month. The OpenStack Cinder interface can assign LUNs to virtual machines, but the new Havana release allows NAS systems to dole out files that act as LUNs, such as OVA or VMDK files. The advantage is that these files can managed by Active Cloud Engine, cached locally across global name space, have policies place them on appropriate storage tiers, and inactive Virtual Machine images can be migrated to less expensive disk or tape.
To learn more, see the [Announcement letter: Storwize Family Software v7.3.0].
You can learn more about the Storwize family at the [IBM Edge Conference], May 19-23, at Las Vegas. I'll be there!
technorati tags: IBM, Announcements, SAN Volume Controller, SVC, Storwize, Storwize V7000, Flex System V7000, Storwize V5000, Storwize V3700, 2145-DH8, hardware-assisted compression, Real-time Compression, Intel QuickAssist, New Storwize, HIC, Easy Tier, Storwize V7000 Unified, File Modules, OpenStack, OpenStack Havana, OpenStack Cinder, multiple-writer, independent-writer, Active Cloud Engine, Windows SFU, Kerberos, Storwize family, #ibmEdge, Las Vegas
Well, it's Tuesday again, and you know what that means! IBM Announcements! Typically, IBM System Storage has three to five major product launches per year. Making announcements every Tuesday would have been two frequent, and having one big announcement every two or three years would be too far apart. Worldwide combined revenues for storage hardware and software grew double digits last year, comparing full-year 2011 to the prior 2010 year, and I am sure that 2012 will also be a good year for IBM as well! This week we have announcements for both disk and tape, but since 2012 is the 60th Diamond Anniversary for tape, I will start with tape systems first.
- TS1140 support for JA/JJ tape cartridges
The TS1140 enterprise tape drive was announced at the [Storage Innovation Executive Summit] last May. It supported a new E07 format on three different new tape cartridges. Models "JC" was 4.0TB standard re-writeable tapes, "JY" was 4.0TB WORM tapes, and "JK" were 500GB economy tapes that were less expensive, but offered faster random access.
Generally, IBM has adopted an N-2 read, N-1 write [backward compatibility]. This means that the TS1140 could read E05 and E06 formatted tapes on JB and JX media, and could write E06 format on JB and JX media. However, there are a lot of older JA and JJ media, especially as part of TS7740 environments, so IBM now supports TS1140 drives to read J1A formatted JA and JJ media. This is not just for TS7740 environments, any TS1140 in stand-alone or tape library configurations will support this as well.
- TS7700 R2.1 enhancements
IBM is a leader in tape virtualization with or without physical tape as back-end media. There are two hardware models of the [IBM Virtualization Engine TS7700 family] for the IBM System z mainframe. These virtual libraries are referred to as "clusters" in IBM literature.
A unique feature of the TS7700 series is support for a Grid configuration, which allows up to six different TS7700 clusters to be grouped into a single instance image. These clusters can be in local or remote locations, connected via WAN or LAN connections.
R2.1 is the latest software release of this successful IBM's TS7700 series.
- True Sync Mode Copy. Before R2.1, the TS7700 offered "immediate mode copy". An application would write to a virtual tape, and when it was done with the tape and performed an unmount, the TS7700 would then replicate the tape contents to a secondary cluster on the grid. With True Sync Mode, data contents are replicated per implicit or explicit SYNC points. This is another IBM first in the IT tape industry.
- Remote Mount Fail-over. When you have two or more TS7700 clusters in a grid configuration, you can do remote mounts. We've added fail-over multi-pathing up to four paths, so that if a link to a remote cluster is down, it will try one of the others instead.
- Parallel Copies and Pre-Migration. On of my 19 patents is for the pre-migration feature for the IBM 3494 Virtual Tape Server (VTS) that carries forward into the TS7700, and is also used in the SONAS and Information Archive products. However, when the grid architecture was introduced, the engineers decided not to allow pre-migration and copies to secondary clusters to occur concurrently. Now these two operations can be done in parallel.
- Merge two grids into one grid. Now that we can support up to six clusters into a single grid, we have people with 2-cluster and 3-cluster grids looking to merge them into one. Of course, all the logical and physical volume serials (VOLSER) must be unique!
- Accelerate off JA/JJ Media. There are a lot of older JA and JJ media still in TS7700 libraries. This feature allows customers to speed up the transition to newer physical tape media.
- Copy Export to E06 format on JB media. This one is clever, and I have to say I would have never thought about it. Let's say you have a TS7740 with TS1140 drives, but you want to export some virtual tapes to physical media to be sent to someone who only has a TS7740 connected with older TS1130 drives. These older drives can't read new JC media nor make sense of the E07 format. This feature will let you export to older JB media in E06 format so that it will be fully readable at the new location on the TS1130 drives.
- Copy Export Merge service offering. Thanks to mergers and acquisitions, it is sometimes necessary to split off a portion of data from a TS7700 grid. In the past, IBM supported sending this export to a completely empty TS7700 library, but this new service offerings allows the export to be merged into an existing TS7700 that already contains data.
- LTFS-SDE support for Mac OS X 10.7 Lion
How do people still not yet know about the Linear Tape File System [LTFS]? I mentioned this in my blogs back in 2010 in [April], [September], and [November]. Last year, LTFS was the [NAB Show Pick Hits Award] and an [Emmy] for revolutionizing the use of digital tape in Television broadcasting.
In layman's terms, the Single Drive Edition [LTFS-SDE] allows a tape cartridge to be treated like USB memory stick. It is supported on the LTO5 tape drives for systems running various levels of Windows, Linux and Mac OS X. Prior to this announcement, IBM supported Snow Leopard (10.5.6) and Leopard (10.6), and now supports Mac OS X 10.7 "Lion" release.
- XIV Gen3 Solid-State Drives (SSD)
The [IBM XIV Gen3 storage system] now supports Solid State Drives! I thought I would provide some context from a historic perspective.
IBM first introduced Solid-State Drives (SSD) back in 2007 where it made sense the most, in [drive-for-drive replacements on blade servers in the IBM BladeCenter]. Blade servers typically only have a single drive, and SSD are both faster and use less energy on a drive-for-drive comparison, so this provided immediate benefit. Today, SSD are available on a variety of System x and POWER system servers.
In 2008, IBM rocked the world by being the first to reach [1 Million IOPS with Project Quicksilver]. This was an all-SSD configuration which many considered unrealistic (at the time), but it showed the potential for solid state drives.
In 2010, IBM announced [DS8700 Easy Tier with Sub-LUN automated tiering], and followed it up with similar support for [SVC 6.1 and Storwize V7000] that provides this enterprise-class functionality to midrange and externally-virtualized storage systems.
In 2011, IBM was able to [scan 10 billion files in 43 minutes] using the GPFS file system in support of Big Data analytics. This, of course, was done with Solid State Drives.
When the [XIV Gen3 was Announced - July 2011], each module included an 1.8-inch "SSD-Ready" slot in the back. IBM made a Statement of Direction that IBM would someday offer SSD drives to put in these slots. Today's announcement is that IBM has finalized the qualification process, so now XIV Gen3 clients can have 400GB of usable non-volatile SSD read cache added to each module. This SSD can be added to existing XIV Gen3 boxes in the field, or it can be factory-installed in new shipments. If you have a 15-module XIV, that's 6TB of additional read cache! This SSD is entirely managed by the XIV Gen3, so you won't have to spend weeks reading manuals or specifying configuration parameters.
My colleague Elisabeth Stahl covers this from a performance angle in her blog post [Performance in a Flash: New IBM XIV SSD Caching].
When you carve volumes on the XIV, you now have an option to enable or disable use of the SSD cache for each volume. Since XIV is being used in private and public cloud deployments, this offers the ability to offer premium performance at premium prices. The use of SSD is complementary to IBM XIV Quality of Service (QoS) performance levels, which are determined by host instead.
Well, that's the first major IBM System Storage launch of 2012. Let me know what you think in the comment section below.
technorati tags: IBM, TS1140, TS7700, TS7720, TS7740, LTFS, LTFS-SDE, LTO5, Mac OS X, Sync, XIV, Gen3, Elisabeth Stahl, SSD
Fellow Blogger BarryB mentions "chunk size" in his post [Blinded by the light
],as it relates to Symmetrix Virtual Provisioning capability. Here is an excerpt:
I mean, seriously, who else but someone who's already implemented thin provisioning would really understand the implications of "chunk" size enough to care?
For those of you who don't know what the heck "chunk size" means (now listen up you folks over at IBM who have yet to implement thin provisioning on your own storage products), a "chunk" is the term used (and I think even trademarked by 3PAR) to refer to the unit of actual storage capacity that is assigned to a thin device when it receives a write to a previously unallocated region of the device.For reference, Hitachi USP-V uses I think a 42MB chunk, XIV NEXTRA is definitely 1MB, and 3PAR uses 16K or 256K (depending upon how you look at it).
Thin Provisioning currently offered in IBM System Storage N serieswas technically "implemented" by NetApp, and that the Thin Provisioning that will be offered in our IBM XIV Nextrasystems will have been acquired from XIV. Lest I remind you that many of EMC's products were developed by other companies first, then later acquired by EMC, so no need for you to throw rocks from your glass houses in Hopkington.
"Thin provisioning" was first introduced by StorageTek in the 1990's and sold by IBM under the name of RAMAC Virtual Array (RVA). An alternative approach is "Dynamic Volume Expansion" (DVE). Rather than giving the host application a huge 2TB LUN but actually only use 50GB for data, DVE was based on the idea that you only give out 50GB they need now, but could expand in place as more space was required. This was specifically designed to avoid the biggest problem with "Thin Provisioning" which back then was called "Net Capacity Load" on the IBM RVA, but today is now referred to as "over-subscription". It gave Storage Administrators greater control over their environment with no surprises.
In the same manner as Thin Provisioning, DVE requires a "chunk size" to work with. Let's take a look:
- DS4000 series
On the DS4000 series, we use the term "segment size", and indicate that the choice of a segment size can have some influence on performance in both IOPS and throughput. Smaller segment sizes increase the request rate (IOPS) by allowing multiple disk drives to respond to multiple requests. Large segment sizes increase the data transfer rate(Mbps) by allowing multiple disk drives to participate in one I/O request. The segment size does not actually change what is stored in cache, just what is stored on the disk itself.It turns out in practice there is no advantage in using smaller sizes with RAID 1; only in a few instances does this help with RAID-5 if you can writea full stripe at once to calculate parity on outgoing data. For most business workloads, 64KB or 128KB are recommended. DVE expands by the same number of segments across all disks in the RAID rank, so for example in a 12+P rank using 128KB segment sizes, the chunk size would be thirteen segments, about 1.6MB in size.
- SAN Volume Controller
On the SAN Volume Controller, we call this "extent size" and allow it to be various values 64MB to 512MB. Initially,IBM only managed four million extents, so this table was used to explain the maximum amount that could be managedby an SVC system (up to 8 nodes) depending on extent size selected.
|Extent Size||Maximum Addressable|
IBM thought that since we externalized "segment size" on the DS4000, we should do the same for the SANVolume Controller. As it turned out, SVC is so fast up in the cache, that we could not measure any noticeable performance difference based on extent size. We did have a few problems. First, clients who chose 16MB andthen grew beyond the 64TB maximum addressable discovered that perhaps they should have chosen something larger.Second, clients called in our help desk to ask what size to choose and how to determine the size that was rightfor them. Third, we allowed people to choose different extent sizes per managed disk group, but that preventsmovement or copies between groups. You can only copy between groups that use the same extent size. The generalrecommendation now is to specify 256MB size, and use that for all managed disk groups across the data center.
The latest SVC expanded maximum addressability to 8PB, still more than most people have today in their shops.
- DS8000 series
Getting smarter each time we introduce new function, we chose 1GB chunks for the DS8000. Based on a mainframebackground, most CKD volumes are 3GB, 9GB, or 27GB in size, and so 1GB chunks simplified this approach. Spreadingthese 1GB chunks across multiple RAID ranks greatly reduced hot-spots that afflict other RAID-based systems.(Rather than fix the problem by re-designing the architecture, EMC will offer to sell you software to help you manually move data around inside the Symmetrix after the hot-spot is identified)
Unlike EMC's virtual positioning, IBM DS8000 dynamic volume expansion does work on CKD volumes for our System z mainframe customers.
The trade-off in each case was between granularity and table space. Smaller chunks allow finer control on the exact amount allocated for a LUN or volume, but larger chunks reduced the number of chunks managed. With our advanced caching algorithms, changes in chunk size did not noticeably impact performance. It is best just to come up with a convenient size, and either configure it as fixed in the architecture, or externalize it as a parameter with a good default value.
Meanwhile, back at EMC, BarryB indicates that they haven't determined the "optimal" chunk size for their newfunction. They plan to run tests and experiments to determine which size offers the best performance, and thenmake that a fixed value configured into the DMX-4. I find this funny coming from the same EMC that won't participate in [standardized SPC benchmarks] because they feel that performance is a personal and private matter between a customer and their trusted storage vendor, that all workloads are different, and you get the idea. Here's another excerpt:
Back at the office, they've taking to calling these "chunks" Thin Device Extents (note the linkage back to EMC's mainframe roots), and the big secret about the actual Extent size is...(wait for it...w.a.i.t...for....it...)...the engineers haven't decided yet!
That's right...being the smart bunch they are, they have implemented Symmetrix Virtual Provisioning in a manner that allows the Extent size to be configured so that they can test the impact on performance and utilization of different sizes with different applications, file systems and databases. Of course, they will choose the optimal setting before the product ships, but until then, there will be a lot of modeling, simulation, and real-world testing to ensure the setting is "optimal."
Finally, BarryB wraps up this section poking fun at the chunk sizes chosen by other disk manufacturers. I don't knowwhy HDS chose 42MB for their chunk size, but it has a great[Hitchiker's Guide to the Galaxy]sound to it, answering the ultimate question to life, the universe and everything. Hitachi probably went to theirDeep Thought computer and asked how big should their "chunk size" be for their USP-V, and the computer said: 42.Makes sense to me.
I have to agree that anything smaller than 1MB is probably too small. Here's the last excerpt:
Now, many customers and analysts I've spoken to have in fact noted that Hitachi's "chunk" size is almost ridiculously large; others have suggested that 3PAR's chunks are so small as to create performance problems (I've seen data that supports that theory, by the way).
Well, here's the thing: the "right" chunk size is extremely dependent upon the internal architecture of the implementation, and the intersection of that ideal with the actual write distribution pattern of the host/application/file system/database.
So my suggestion to EMC is, please, please, please take as much time as you need to come up with the perfect"chunk size" for this, one that handles all workloads across a variety of operating systems and applications, from solid-state Flash drives to 1TB SATA disk. Take months or years, as long as it takes. The rest of the world is in no hurry, as thin provisioning or dynamic volume expansion is readily available on most other disk systems today.
Maybe if you ask HDS nicely, they might let you ask their computer.
technorati tags: IBM, thin provisioning, XIV, Nextra, N series, chunk size, BarryB, EMC, Symmetrix, virtual provisioning, 3PAR, Hitachi, HDS, USP-V, StorageTek, RAMAC Virtual Array, RVA, dynamic volume expansion, DVE, 42MB, Hitchhiker's Guide, CKD, System z, mainframe, SATA, DS8000, DS4000, SAN Volume Controller, SVC
Continuing my coverage of the annual [2010 System Storage Technical University], I attended some sessions from the System x and Federal track side of this conference.
- Grid, SOA and Cloud Computing
Bill Bauman, IBM System x Field Technical Support Specialist and System x University celebrity, presented the differences between Grid, SOA and Cloud Computing. I thought this was an odd combination to compare and contrast, but his presentation was well attended.
- Grid - this is when two or more independently owned and managed computers are brought together to solve a problem. Some research facilities do this. IBM helped four hospitals connect their computers together into a grid to help analyze breast cancer. IBM also supports the [World Community Grid] which allows your personal computer to be connected to the grid and help process calculations.
- SOA - SOA, which stands for Service Oriented Architecture, is an approach to building business applications as a combination of loosely-coupled black-box components orchestrated to deliver a well-defined level of service by linking together business processes. I often explain SOA as the the business version of Web 2.0. You can download a free copy of the eBook "SOA for Dummies" at the [IBM Smart SOA] landing page.
- Cloud - A Cloud is a dynamic, scalable, expandable, and completely contractible architecture. It may consist of multiple, disparate, on-premise and off-premise hardware and virtualized platforms hosting legacy, fully installed, stateless, or virtualized instances of operating systems and application workloads.
Bill has his own blog, and has an interesting post [Cloud Computing, What it Is, and What it is Not] that appears to be the basis of this presentation.
- Chaos to Cloud
Tom Vezina, IBM Advanced Technical Sales Specialist, presented "Chaos to Cloud Computing". Survey results show that roughly 70 percent of cloud spend will be for private clouds, and 30 percent for public, hybrid or community clouds. Of the key motivations for public cloud, 77 percent or respondents cited reducing costs, 72 percent time to value, and 50 percent improving reliability.
Tom ran over 500 "server utilization" studies for x86 deployments during the past eight years. Of these, the worst was 0.52 percent CPU utilization, the best was 13.4 percent, and the average was 6.8 percent. When IBM mentions that 85 percent of server capacity is idle, it is mostly due to x86 servers. At this rate, it seems easy to put five to 20 guest images onto a machine. However, many companies encounter "VM stall" where they get stuck after only 25 percent of their operating system images virtualized.
He feels the problem is with the fact most Physical-to-Virtual (P2V) migrations are manual efforts. There are tools available like Novell [PlateSpin Recon] to help automate and reduce the total number of hours spent per migration.
- System x KVM Solutions
Boy, I walked into this one. Many of IBM's cloud offerings are based on the Linux hypervisor called Kernel-based Virtual Machine [a href="http://www.linux-kvm.org/page/Main_Page">KVM] instead of VMware or Microsoft Hyper-V. However, this session was about the "other KVM": keyboard video and mouse switches, which thankfully, IBM has renamed to Console Managers to avoid confusion. Presenters Ben Hilmus (IBM) and Steve Hahn (Avocent) presented IBM's line of Local Console Managers (LCM) and Global Console Managers (GCM) products.
LCM are the traditional KVM switches that people are familiar with. A single keyboard, video and mouse can select among hundreds of servers to perform maintenance or check on status. GCM adds KVM-over-IP capabilities, which means that now you can access selected systems over the Ethernet from a laptop or personal computer. Both LCM and GCM allow for two-level tiering, which means that you can have an LCM in each rack, and an LCM or GCM that points to each rack, greatly increasing the number of servers that can be managed from a single pane of glass.
Many severs have a "service processor" to manage the rest of the machine. IBM RSA II, HP iLO, and Dell DRAC4 are some examples. These allow you to turn on and off selected servers. IBM BladeCenter offers an Management Module that allows the chassis to be connected to a Console Manager and select a specific blade server inside. These can also be used with VMware viewer, Virtual Network Computing (VNC), or Remote Desktop Protocol (RDP).
IBM's offerings are unique it that you can have an optical CD/DVD drive or USB external storage attached at the LCM or GCM, and make it look like the storage is attached to the selected server. This can be used to install or upgrade software, transfer log files, and so on. Another great use, and apparently the motivation for having this session in the "Federal Track", is that the USB can be used to attach a reader for a smart card, known as a Common Access Card [CAC] used by various government agencies. This provides two-factor authentication [TFA]. For example, to log into the system, you enter your password (something you know) and swipe your employee badge smart card (something you have). The combination are validated at the selected server to provide access.
I find it amusing that server people limit themselves to server sessions, and storage people to storage sessions. Sometimes, you have to step "outside your comfort zone" and learn something new, something different. Open your eyes and look around a bit. You might just be surprised what you find.
(FTC note: I work for IBM. IBM considers Novell a strategic Linux partner. Novell did not provide me a copy of Platespin Recon, I have no experience using it, and I mention it only in context of the presentation made. IBM resells Avocent solutions, and we use LCM gear in the Tucson Executive Briefing Center.)
technorati tags: IBM, Technical University, Grid, SOA, Cloud Computing, P2V, VMware, Novell, Platespin, x86, KVM, LCM, GCM, Avocent, CAC, TFA
My colleagues, Harley Puckett (left) and Jack Arnold (right) were highlighted in today's Arizona Daily Star, our local newspaper, as part of an article on IBM's success and leadership in the IT storage industry. At 1400 employees here in Tucson, IBM is Southern Arizona's 36th largest employer.
Highlighted in the article:
- DS8700 with the new Easy Tier feature
- TS7650 ProtecTIER virtual tape library with data deduplication capability
- LTO-5 tape and the new Long Term File System (LTFS)
- XIV with the new 2TB drive, for a maximum per-rack usable capacity of 161 TB.
Read the full article [IBMers Crank Out 4 New Offerings To Handle Data Deluge]
technorati tags: , Arizona Daily Star, IBM Tucson, DS8700, Easy Tier, ProtecTIER, Deduplication, LTO-5, LTFS, XIV, IBM, Tucson, Arizona
Well it's Tuesday again, and you know what that means... IBM announcements! Yesterday, at the IBM Edge conference here in Orlando, Florida, IBM announced its new apporach to storage, and a whole bunch of storage products, enhancements, and services. I will focus on some key ones here, and save the rest for next week.
- IBM SAN Volume Controller (SVC) v6.4
The SVC is IBM's enterprise-class storage hypervisor. The latest software release, v6.4, can be installed on any SVC hardware, from the 2145-8F2 introduced back in 2005, to newer models like the 2145-CG8. Here are the key features:
- Fibre Channel over Ethernet (FCoE) -- This is complete end-to-end support. For SVC units with 10GbE ports, these ports can be now be used for FCoE. This allows hosts to attach to SVC via FCoE, allows SVC node-to-node communication for clustering, and allows SVC to communicate to back-end devices via FCoE.
- Real-Time Compression -- IBM ported over the patent Random Access Compression Engine (RACE) from the Real-Time Compression Appliances to SVC v6.4. This allows primary data, accessed via block-based protocols, to be compressed up to 80 percent. This feature is an extra priced feature by TB.
- Non-Disruptive Volume move between I/O Groups -- If you don't already have SVC, you don't need to worry about this. For existing SVC customers, this allows volumes to be associated with two or more I/O groups, and that you can add or remove I/O groups non-disruptively. For example, if you want to move a volume from IOG1 to IOG2, then you add IOG2 to the list of I/O groups for the volume, let the multi-pathing software discover the additional paths, the remove IOG1, which then marks the previous IOG1 paths inactive. All this can be done while applications read and write data.
- Dedicate FCP ports for Replication -- If you activate the two 10GbE Ethernet ports for FCoE, you can free up two FCP ports that you can dedicate for long-distance Metro Mirror or Global Mirror.
If you have SVC today, but are running an old release like v4.3 or v5.1, I recommennd you upgrade up to at least v6.2.05 release now. This release has been out for a year and is very stable, and serves as a great platform for a later upgrade to SVC v6.4.
- IBM Storwize V7000 v6.4
The Storwize V7000 is IBM's midrange storage hypervisor. The latest software release, v6.4, can be installed on existing block-only Storwize V7000 units in the field. The Storwize V7000 v6.4 gets all the features listed above, as well as the following:
- Four-way clustering -- Previously, you could cluster two Storwize V7000 controller enclosures together (4 canisters total). To cluster three or four controllers required an RPQ. Now, IBM supports up to four Storwize V7000 controller enclosures (8 canisters) without an RPQ.
- Direct Fibre Channel attach -- A lot of people are using Storwize V7000 inside single-rack configurations, so it makes sense not to require a SAN switch for just a few Windows, Linux or VMware servers. An RPQ is now available to allow this to happen.
- IBM Tivoli Storage Productivity Center (TPC) v5.1
TPC is already ranked one of the best Storage Infrastructure Management software in the market, and this release will just solidify its lead. Key features include:
- Upward integration to higher level management systems
- A new, intuitive, easy-to-use web-based GUI inspired by the XIV GUI
- Integration of COGNOS to be able to generate and customize reports
- Support for SONAS systems
There are several presentations on TPC this week that will go into more detail. Check out the [TPC Facebook page].
- My latest book Inside System Storage: Volume IV is now available!
Yes, can you believe it? I have published my fourth volume in my "Inside System Storage" series! It is available in three formats:
- Hardcover with dust jacket
- eBook (Adobe Acrobat PDF)
You can order this, and all my other books, in all formats, directly from my [Author Spotlight] page. The paperback will also be available soon from other online booksellers, search for ISBN 978-1-105-72213-4.
- IBM DS3500 Express
The DS3500 is our entry-level block-based device, designed specifically for random I/O workloads. This includes databases, email repositories, traditional business applications, and on-line transactional workloads. Here are the new features:
- Dynamic Disk Pooling, similar to what XIV does to reduce disk rebuild times, but using a RAID-6 like approach per chunk of data.
- Thin Provisioning using Dynamic Disk Pooling
- Asynchronous Logical Unit Access (ALUA) failover
- Enhanced FlashCopy, improved scalability, consistency groups and rollback support
- VMware API for Array Integration (VAAI) support. This includes Write Same, Extended Copy, and Atomic Test & Set.
The DS3500 replaces the previous models of DS3200, DS3300 and DS3400 models.
- IBM DCS3700
The DCS3700 is our entry-level/midrange block-based device, replacing the DCS9900 model, designed specifically for sequential I/O workloads. This includes Big Data analytics, Hadoop, High Performance Computing (HPC), video surveillance, and television broadcasting. It holds 60 drives in a 4U controller enclosure.
For more on any of these announcements, see the [June 4th Announcement Page], or follow the Twitter tag #transformITnow.
technorati tags: IBM, SVC, Storwize V7000, Tivoli Storage, Productivity Center, TPC, DS3500, DCS37000
Back in Februray, my blog post [A Box Full of Floppies] mentioned that I uncovered some diskettes compressed with OS/2 Stacker. Jokingly, I suggested that I may have to stand up an OS/2 machine just to check out what is actually on those floppies. Each floppy contains only three files: README.STC, STACKER.EXE and a hidden STACKVOL.DSK file. The README.STC explains that the disk is compressed by Stacker, a program developed by [Stac Electronics, Inc.]. The STACKER.EXE would not run on Windows XP, Vista or Windows 7. The STACKVOL.DSK is just a huge binary file, like a ZIP file, compressed with [Lempel-Ziv-Stac] algorithm that combines Lempel-Ziv with Huffman coding.
In my follow-up post [Like Sands in an Hourglass], I explained how there are many ways I could have tackled this project. I could either use the Emulation approach and try to build an OS/2 guest image under a hypervisor like VMware, KVM or VirtualBox, or just take the Museum approach and try taking one of my half dozen old machines, wipe it clean and stand up OS/2 on it bare metal. This turned out to be more challenging than I expected. The systems I have that are modern and powerful enough to run hypervisors don't have floppy drives, so I opted for the Museum approach.
(A quick [history of OS/2] might be helpful. IBM and Microsoft jointly developed OS/2 back in 1985. By 1990, Microsoft decided it's own Windows operating system was more popular with the ladies, and decided to break off with IBM. In 1992, IBM release OS/2 version 2.0, touted as "a better DOS than DOS and a better Windows than Windows!" Both parties maintained ownership rights, Microsoft renamed OS/2 to Windows NT. The "NT" stood for New Technology, the basis for all of the enterprise-class Windows servers used today. IBM named its version of OS/2 version 3 and 4 "WARP", with the last version 4.52 released in 2001. In its heyday, OS/2 ran the majority of Automated Teller Machines (ATMs), was used for hardware management consoles (HMC), and was used worldwide to run various Railway systems. After 2001, IBM encouraged people to transition from Windows or OS/2 over to Java and Linux. For those that can't or won't leave OS/2, IBM partnered with Serenity Systems to continue OS/2 under the brand [eComStation].)
Working with an IBM [ThinkCentre 8195-E2U Pentium 4 machine] with 640MB RAM and 80GB hard disk, a CD-rom and one 3.5-inch floppy drive, I first discovered that OS/2 is limited to very small amounts of hard disk. There are limits on [file systems and partition sizes] as well as the infamous [1024-cylinder limit] for bootable operating systems. Having a completely empty drive didn't work, as the size of the disk was too big. Carving out a big partition out of this also failed, as it exceeded the various limits. Each time, it felt the partition table was corrupted because the values were so huge. Even modern Disk Partitioning tools ([SysRescueCD] or [PartedMagic]) didn't work, as these create partitions not recognizable to OS/2.
The next obstacle I knew I would encounter would be device drivers. OS/2 comes as a set of three floppy diskettes and a CD-rom. The bootable installation disk was referred to affectionately as "Disk 0", then Disk 1, then Disk 2. Once all drivers have been loaded into memory, then it can start looking at the CDrom, and continue with the installation. In searching for updated drivers, I came across [Updated OS/2 Warp 4 Installation Diskettes] to address problems with newer display monitors. It also addresses the 8.4GB volume limit.
The updates were in the form of EXE files that only execute in a running DOS or OS/2 environment, expanded onto a floppy diskette. It seemed like [Catch-22], I need a working DOS or OS/2 system to run the update programs to create the diskettes, but need the diskettes to build a working system.
To get around this, I decided to take a "scaffolding" approach. Using DOS 6 bootable floppy, I was able to re-partition the drive with FDISK into two small 1.9GB partitions. I have the full five-floppy IBM DOS 6 set, I hid the first partition for OS/2, and install the DOS 6 GUI on the second partition. I went ahead and added a few new subdirectories: BOOT to hold Grub2, PERSONAL to hold the data I decompress from the floppies, and UTILS to hold additional utilities. This little DOS system worked, and I now have new OS/2 "Disk 1" and "Disk 2" for the installation process.
(If you don't have a full set of DOS installation diskettes, you can make due with "FORMAT C: /S" from a [DOS boot disk], and then just copy over all the files from the boot disk to your C: drive. You won't have a nice DOS GUI, but the command line prompt will be enough to proceed.)
Like DOS, OS/2 expects to be installed on the C: drive. I hid the second partition (DOS), and marked the first partition installable and bootable. The OS/2 installation involves a lot of reboots, and the hard drive is not natively bootable in the intermediate stages. This means having to boot from Disk 0, then putting in Disk 1, then disk 2, before continuing the next phase of the installation. I tried to keep the installation as "Plain Vanilla" as possible.
I had to figure out what to include, and what to exclude, and this involved a lot of trial and error. For example, one of the choices was for "external diskette support". Since I had an "internal diskette drive", I didn't think I needed it. But after a full install, I discovered that it would not read or write floppy diskettes, so it appears that I do indeed need this support.
OS/2 supports two different file systems, FAT16 and the High Performance File System (HPFS). Since my partition was only 1.9GB in size, I chose just to use FAT16. HPFS supported larger disk partitions, longer file names, and faster performance, none of which I need for these purposes.
I thought it would be nice to get TCP/IP networking to work with my Ethernet card. However, after many attempts, I decided against this. I needed to focus on my mission, which was to decompress floppy diskettes. It was amusing to see that OS/2 supported all kinds of networking, including Token Ring, System Management, Remote Access, Mobile Access Services, File and Print.
Once all the options are chosen, OS/2 installation then proceeds to unpack and copy all the programs to the C: drive. During this process, IBM had informational splash screens. Here's one that caught my eye, titled "IBM Means Three Things" that listed three reasons to partner with IBM:
- Providing global solutions for a small planet
- Creating and Applying advanced technologies to improve with which customers run their businesses
- Constantly improving customer service with the products and services we provide
You might wonder how these OS/2 splash screens, written over 10 years ago, can appear almost identical to IBM's current [Smarter Planet] campaign. Actually, it is not that odd. IBM has been keeping to these same core principles since 1911, only the words to describe and promote these core values have changed.
To access both OS/2 and DOS partitions, I installed Grand Unified Bootloader [Grub2] on the DOS partition under C:/BOOT/GRUB directory. However, when I boot OS/2, I cannot see the DOS partition. And when I boot DOS, I cannot see the OS/2 partition. Each operating system thinks its C: drive is the only partition on the system.
Now that I had OS/2 running, I was then able to install Stacker from two floppy diskettes. With this installed, I can compress and decompress data on either the hard disk, or on floppy diskettes. Most of the files were flat text documents and digital photos. After copying the data off the compressed disks onto my hard drive, I now can copy them off to a safe place.
To finish this project, I installed Ubuntu Linux on the remaining 76GB of disk space, which can access both the OS/2 and DOS drives FAT16 file systems natively. This allows me to copy files from OS/2 to DOS or vice versa.
Now that I know what data types are on the diskettes, I determined that I could have decompressed the data in just a few steps:
- Set up a DOS partition on C: drive
- Insert one of the compressed diskettes into the floppy drive
- Copy the STACKER.EXE program from the floppy to the C: drive
- Run "STACKER A:" to decompress the floppy diskette
However, now that I have a working DOS and OS/2 system, I can possibly review the rest of my floppy diskettes, some of which may require running programs natively on OS/2 or DOS. This brings me to an important lesson. If you are going to keep archive data for long-term retention, you need to choose file formats that can be read by current operating systems and programs. Installing older operating systems and programs to access proprietary formats can be quite time-consuming, and may not always be possible or desirable.
technorati tags: IBM, Stac, Stacker, OS/2, DOS, Microsoft, Windows, ThinkCentre, Compression, Liv-Zempel
This week, I am in beautiful Sao Paulo, Brazil, teaching Top Gun class to IBM Business Partners and sales reps. Traditionally, we have "Tape Thursday" where we focus on our tape systems, from tape drives, to physical and virtual tape libraries. IBM is the number #1 tape vendor, and has been for the past eight years.
(The alliteration doesn't translate well here in Brazil. The Portuguese word for tape is "fita", and Thursday here is "quinta-feira", but "fita-quinta-feira" just doesn't have the same ring to it.)
In the class, we discussed how to handle common misperceptions and myths about tape. Here are a few examples:
- Myth 1: Tape processing is manually intensive
In my July 2007 blog post [Times a Million], I coined the phrase "Laptop Mentality" to describe the problem most people have dealing with data center decisions. Many folks extend linearly their experiences using their PCs, workstations or laptops to apply to the data center, unable to comprehend large numbers or solutions that take advantage of the economies of scale.
For many, the only experience dealing with tape was manual. In the 1980s, we made "mix tapes" on little cassettes, and in the 1990s we recorded our favorite television shows on VHS tapes in the VCR. Today, we have playlists on flash or disk-based music players, and record TV shows on disk-based video recorders like Tivo. The conclusion is that tapes are manual, and disk are not.
Manual processing of tapes ended in 1987, with the introduction of a silo-like tape library from StorageTek. IBM quickly responded with its own IBM 3495 Tape Library Data Server in 1992. Today, clients have many tape automation choices, from the smallest IBM TS2900 Tape Autoloader that has one drive and nine cartridges, all the way to the largest IBM TS3500 multiple-library shuttle complex that can hold exabytes of data. These tape automation systems eliminate most of the manual handling of cartridges in day-to-day operations.
- Myth 2: Tape media is less reliable than disk media
For any storage media to be unreliable is to return the wrong information that is different than what was originally stored. There are only two ways for this to happen: if you write a "zero" but read back a "one", or write a "one" and read a "zero". This is called a bit error. Every storage media has a "bit error rate" that is the average likelihood for some large amount of data written.
According to the latest [LTO Bit Error rates, 2012 March], today's tape expects only 1 bit error per 10E17 bits written (about 100 Petabytes). This is 10 times more reliable than Enterprise SAS disk (1 bit per 10E16), and 100 times more reliable than Enterprise-class SATA disk (1 bit per 10E15).
Tape is the media used in "black boxes" for airplanes. When an airplane crashes, the black box is retrieved and used to investigate the causes of the crash. In 1986, the Space Shuttle Challenger exploded 73 seconds after take-off. The tapes in the black box sat on the ocean floor for six weeks before being recovered. Amazingly, IBM was able to successfully restore [90 percent of the block data, and 100 percent of voice data].
- Myth 3: Most tape restores fail
Why do people still believe that most tape restores fail? Curtis Preston, on his Backup Central blog, has a great post [Gartner Never Said 71 percent of Tape Restores Fail].
Analysts are quite upset when they are quoted out of context, but in this case, Gartner never said anything closely similar to this. Nor did the other analysts that Curtis investigated for similar claims. What Garnter did say was that disk provides an attractive alternative storage media for backup which can increase the performance of the recovery process.
Back in the 1990s, Savur Rao and I developed a patent to help backup DB2 for z/OS by using the FlashCopy feature of IBM's high-end disk system. The software method to coordinate the FlashCopy snapshots with the database application and maintain multiple versions was implemented in the DFSMShsm component of DFSMS. A few years later, this was part of a set of patents IBM cross-licensed to Microsoft for them to implement a similar software for Windows called Data Protection Manager (DPM). IBM has since introduced its own version for distributed systems called IBM Tivoli FlashCopy Manager that runs not just on Windows, but also AIX, Linux, HP-UX and Solaris operating systems.
Curtis suspects the "71 percent" citation may have been propogated by an ambitious product manager of Microsoft's Data Protection Manager, back in 2006, perhaps to help drive up business to their new disk-based backup product. Certainly, Microsoft was not the only vendor to disparage tape in this manner.
A few years ago, an [EMC failure brought down the State of Virginia] due to not just a component failure it its production disk system, but then made it worse by failing to recover from the disk-based remote mirror copy. Fortunately, the data was able to be restored from tape over the next four days. If you wonder why nobody at EMC says "Tape is Dead" anymore, perhaps it is because tape saved their butts that week.
(FTC Disclosure: I work for IBM and this post can be considered a paid, celebrity endorsement for all of the IBM tape and software products mentioned on this post. I own shares of stock in both IBM and Google, and use Google's Gmail for my personal email, as well as many other Google services. While IBM, Google and Microsoft can be considered competitors to each other in some areas, IBM has working relationships with both companies on various projects. References in this post to other companies like EMC are merely to provide illustrative examples only, based on publicly available information. IBM is part of the Linear Tape Open (LTO) consortium.)
Last year, Google lost the email data for half a million Gmail accounts due to a software error. Once again, tape came to the rescue, with [Google restoring lost Gmail data from tape backups].
- Myth 4: Vendors and Manufacturers are no longer investing in tape technology
IBM and others are still investing Research and Development (R&D) dollars to improve tape technology. What people don't realize is that much of the R&D spent on magnetic media can be applied across both disk and tape, such as IBM's development of the Giant Magnetoresistance read/write head, or [GMR] for short.
Most recently, IBM made another major advancement with tape with the introduction of the Linear Tape File Systems (LTFS). This allows greater portability to share data between users, and between companies, but treating tape cartridges much like USB memory sticks or pen drives. You can read more in my post [IBM and Fox win an Emmy for LTFS technology]!
Next month, IBM celebrates the 60th anniversary for tape. It is good to see that tape continues to be a vibrant part of the IT industry, and to IBM's storage business!
technorati tags: IBM, Google, Microsoft, EMC, Brazil, LTO, TS2900, TS3500, Space Shuttle, Challenger
In my presentations in Australia and New Zealand, I mentioned that people were re-discovering the benefits of removable media. While floppy diskettes were convenient way of passing information from one person to another, they unfortunately did not have enough capacity. In today's world, you may need Gigabytes or Terabytes of re-writeable storage with a file system interface that can easily be passed from one person to another. In this post, I explore three options.
- Cirago CDD2000 Docking Station
The good folks over at [Cirago International Ltd.] sent me a cute little [CDD2000 docking station] for evalution.
(FCC Disclaimer: I work for IBM, and IBM has no business relationship with Cirago at the time of this writing. Cirago has not paid me to mention their product, but instead provided me a free loaner that I promised to return to them after my evaluation is completed. This post should not be considered an endorsement for Cirago's products. List prices for Cirago and IBM products were determined from publicly available sources for the United States, and may vary in different countries. The views expressed herein may not necessarily reflect the views and opinions of either IBM or Cirago.)
I took a few photos so you can see what exactly this device looks like. Basically, it is a plastic box that holds a single naked disk drive. It has four little rubber feet so that it does not slip on your desk surface.
The inside is quite simple. The power and SATA connections match those of either a standard 3.5 inch drive, or the smaller form factor (SFF) 2.5 inch drive. However, to my dismay, it does not handle EIDE drives which I have a ton of. After taking apart six different computer systems, I found only one had SATA drives for me to try this unit out with.
The unit comes with a USB cable and AC/DC power adapter. In my case, I found the USB 3.0 cable too short for my liking. My tower systems are under my desk, but I like keeping docking stations like this on the top of the desk, within easy reach, but that wasn't going to happen because the USB cable was not long enough.
Instead, I ended up putting it half-way in between, behind my desk, sitting on another spare system. Not ideal, but in theory there are USB-extension cables that probably could fix this.
Here it is with the drive inside. I had a 3.5 inch Western Digital [1600AAJS drive] 160 GB, SATA 3 Gbps, 8 MB Cache, 7200 RPM.
To compare the performance, I used a dual-core AMD [Athlon X2] system that I had built for my 2008 [One Laptop Per Child] project. To compare the performance, I ran with the drive externally in the Cirago docking station, then ran the same tests with the same drive internally on the native SATA controller. Although the Cirago documentation indicated that Windows was required, I used Ubuntu Linux 10.04 LTS just fine, using the flexible I/O [fio] benchmarking tool against an ext3 file system.
- Sequential Write - a common use for external disk drive is backup.
- Random read - randomly read files ranging from 5KB to 10MB in size.
- Random mixed - randomly read/write files (50/50 mix) ranging from 5KB to 10MB in size.
|Sequential Write||Throughput IOPS||1119||1044|
| ||Latency (msec)||0.866 ms||0.948 ms|
| ||Bandwidth (KB/s)||16900||14400|
|Random Read||Throughput (IOPS)||164||119|
| ||Latency (msec)||6.06 ms||8.36 ms|
| ||Bandwidth (KB/s)||658||477|
|Random Mixed (50/50)||Throughput (IOPS)||112||81|
| ||Latency (msec) read||8.78 ms||12.1 ms|
| ||Latency (msec) write||0.0983 ms||0.120 ms|
| ||Bandwidth (KB/s) read||557||328|
| ||Bandwidth (KB/s) write||556||337|
For sequential write, the Cirago performed well, only about 15 percent slower than native SATA. For random workloads, however, it was 30-40 percent slower. If you are wondering why I did not get USB 3.0 speeds, there are several factors involved here. First, with overheads, 5 Gbps USB 3.0 is expected to get only about 400 MB/sec. My SATA 2.0 controller maxes out at 375 MB/sec, and my USB 2.0 ports on my system are rated for 57 MB/sec, but with overheads will only get 20-25 MB/sec. Most spinning drives only get 75 to 110 MB/sec. Even solid-state drives top out at 250 MB/sec for sustained activity. Despite all that, my internal SATA drive only got 16 MB/sec, and externally with the Cirago 14 MB/sec in sustained write activity.
Here is the mess that is inside my system. The slot for drive 2 was blocked by cables, memory chips and the heat sink for my processor. It is possible to damage a system just trying to squeeze between these obstacles.
However, the point of this post is "removable media". Having to open up the case and insert the second drive and wire it up to the correct SATA port was a pain, and certainly a more difficult challenge than the average PC user wishes to tackle.
Price-wise, the Cirago lists for $49 USD, and the 160GB drive I used lists for $69, so the combination $118 is about what you would pay for a fully integrated external USB drive. However, if you had lots of loose drives, then this could be more convenient and start to save you some money.
- IBM RDX disk backup system
Another problem with the Cirago approach is that the disk drives are naked, with printed circuit board (PCB) exposed. When not in the docking station, where do you put your drive? Did you keep the [anti-static ESD bag] that it came in when you bought it? And once inside the bag, now what? Do you want to just stack it up in a pile with your other pieces of equipment?
To solve this, IBM offers the RDX backup system. These are fully compatible with other RDX sytems from Dell, HP, Imation, NEC, Quantum, and Tandberg Data. The concept is to have a docking station that takes removable, rugged plastic-coated disk-enclosed cartridges. The docking station can be part of the PC itself, similar to how CD/DVD drives are installed, or as a stand-alone USB 2.0 system, capable of processing data up to 25 MB/sec.
The idea is not new, about 10 years ago we had [Iomega "zip" drives] that offered disk-enclosed cartridges with capacities of 100, 250 and 750MB in size. Iomega had its fair share of problems with the zip drive, which were ranked in 2006 as the 15th worst technology product of all time, and were eventually were bought out by EMC two years later (as if EMC has not had enough failures on its own!)
The problem with zip drives was that they did not hold as much as CD or DVD media, and were more expensive. By comparison, IBM RDX cartridges come in 160GB to 750GB in size, at list prices starting at $127 USD.
- IBM LTO tape with Long-Term File System
Removable media is not just for backup. Disk cartridges, like the IBM RDX above, had the advantage of being random access, but most tape are accessed sequentially. IBM has solved this also, with the new IBM Long Term File System [LTFS], available for LTO-5 tape cartridges.
With LFTS, the LTO-5 tape cartridge now can act as a super-large USB memory stick for passing information from one person to the next. The LTO-5 cartridge can handle up to 3TB of compressed data at up to SAS speeds of 140 MB/sec. An LTO-5 tape cartridge lists for only $87 USD.
The LTO-5 drives, such as the IBM [TS2250 drive] can read LTO-3, LTO-4 and LTO-5cartridges, and can write LTO-4 and LTO-5 cartridges, in a manner that is fully compatible with LTO drives from HP or Quantum. LTO-3, LTO-4 and LTO-5 cartridges are available in WORM or rewriteable formats. LTO-4 and LTO-5 cartridges can be encrypted with 256-bit AES built-in encryption. With three drive manufacturers, and seven cartridge manufacturers, there is no threat of vendor lock-in with this approach.
These three options offer various trade-offs in price, performance, security and convenience. Not surprisingly, tape continues to be the cheapest option.
technorati tags: IBM, Cirago, CDD2000, RDX, Ubuntu, Linux, LTO, LTO-5, LTFS, SATA, USB, fio
Wrapping up this week's theme on the XO laptop, I decided to take on thechallenge of printing. I managed to print from my XO laptop to my laserjet printer.I checked the One Laptop Per Child [OLPC
] website,and found there is no built-in support for printers, but there have been several peopleasking how to print from the XO, so here are the steps I did to make it happen.
(Note: I did all of these steps successfully on my Qemu-emulated system first, and then performed them on my XO laptop)
- Step 1: Determine if you have an acceptable printer
The XO laptop can only connect to a printer via USB cable or over the network.Check your printer to see if it supports either of these two options. In my case, my printer is connected to my Linksys hub that offers Wi-Fi in my home.
The XO runs a modified version of Red Hat's Fedora 7, so we need to also determineif the printer is supported on Linux.Check the [Open Printing Database]for the level of support. This database has come up with the following ranking system.Printers are categorized according to how well they work under Linux and Unix. The ratings do not pertain to whether or not the printer will be auto-recognized or auto-configured, but merely to the highest level of functionality achieved.
- Perfectly - everything the printer can do is working also under Linux
- Mostly - work almost perfectly - funny enhanced resolution modes may be missing, or the color is a bit off, but nothing that would make the printouts not useful
- Partially - mostly don't work; you may be able to print only in black and white on a color printer, or the printouts look horrible
- Paperweight - These printers don't work at all. They may work in the future, but don't count on it
If your printer only supports a parallel cable connection, or does not have a high enough ranking above, go buy another printer. The [Linux Foundation] websiteoffers a list of suggested printers and tutorials.
In my case, I have a Brother HL5250-DN black-and-white laserjet printer connected over a network to Windows XP, OS X and my other Linux systems. It is rated as supporting Linux perfectly, so I decided to use this for my XO laptop.
- Step 2: Install Common UNIX Printing System (CUPS)
Technically, Linux is not UNIX, but for our purposes, close enough. Start the Terminalactivity, use "su" to change to root, and then use "yum" to install CUPS. Yum will automatically determine what other packages are needed, in this case paps and tmpwatch. Once installed, use "/usr/sbin/cupsd" to get the CUPS daemon started, and add this to the end ofrc.local so that it gets started every time you reboot.
Click graphic on the left to see larger view
[olpc@xo-10-CC-6F ~]$ subash-3.2# yum install cups...Total download size = 3.0 MIs this OK [y/N]? y
bash-3.2# /usr/sbin/cupsdbash-3.2# echo "/usr/sbin/cupsd" >> /etc/rc.d/rc.localbash-3.2# exit[olpc@xo-10-CC-6F ~]$
- Step 3: Install Opera or Firefox browser
To download the appropriate drivers, you may need a browser that can handle file downloads. I have triedto do this with the built-in Browse activity (aka Gecko) but encountered problems. I have both Opera and Firefox installed, but I will focus on Opera for this effort.I also installed the older220.127.116.11 version of the Flash player (worked better than the latest 18.104.22.168 version) and Java JRE.Follow the OLPC Wiki instructions for [Opera, Adobe Flash,and Sun Java] installation, thenverify with the following [Java and Flash] testers.
- Step 4: Download drivers and packages unique for your printer
In my case, I used Opera to get to the [Brother Linux Driver Homepage], and downloaded the RPM's for LPR and CUPS wrapper. These are the ones listed under "Drivers for Red Hat, Mandrake (Mandriva), SuSE". I saved these under "/home/olpc" directory.
[olpc@xo-10-CC-6F ~]$ subash-3.2# cd /home/olpcbash-3.2# rpm -vi brhl5250dnlpr-2.0.1-1.i386.rpmbash-3.2# rpm -vi cupswrapperHL5250DN-2.0.1-1.i386.rpmbash-3.2# exit[olpc@xo-10-CC-6F ~]$
- Step 5: Create a "root" password
By default, the root user has no password. However, you will need it to be something for later steps,so here is the process to create a root password. I set mine to "tony" which normallywould be considered too simple a password, but ignore those messages and continue.We will remove it in step 8 (below) to put things back to normal.
[olpc@xo-10-CC-6F ~]$ subash-3.2# passwdChanging password for user root.New UNIX password: tonyBAD PASSWORD: it is too shortRetype new UNIX password: tonypasswd: all authentication tokens updated successfullybash-3.2# exit[olpc@xo-10-CC-6F ~]$
- Step 6: Launch CUPS administration
Here I followed the instructions in Robert Spotswood's [Printing In Linux with CUPS] tutorial.Launch the Opera browser, and enter "http://localhost:631/admin" as the URL. The localhostrefers to the laptop itself, and 631 is the special port that CUPS listens to from browsers. You can alsouse 127.0.0.1 as a shortcut for "localhost", and can be used interchangeably.
In my case, it detected both of my networked printers, so I selected the HL5250DN, entered thelocation of my PPD file "/usr/share/cups/model/HL5250DN.ppd" that was created in Step 4. I set the URI to "lpd://192.168.0.75/binary_p1" per the instructions [Network Setting in CUPS based Linux system] in the Brother FAQ page. I chage the page size from "A4" to "Letter".I set this printer as the default printer. When it asks for userid and password, that is whereyou would enter "root" for the user, and "tony" or whatever you decided to set your root password to.
Select "Print a Test Page" to verify that everything is working.
- Step 7: Printing actual files
Sadly, I don't know Opera well enough to know how to print from there. So, I went over to my trustedFirefox browser. Select File->Page Setup to specify the settings, File->Print Preview tosee what it will look like, and then File->Print to send it to the printer.
To print the file "out.txt" that is in your /home/olpc directory, for example, enter"file:///home/olpc/out.txt" as the URL of the firefox browser. This will show the file,which you can then print to your printer. I had to specify 200% scaling otherwise the fontswere too small to read.
- Step 8: Remove the "root" password
If you want to remove the root password, here are the steps.
[olpc@xo-10-CC-6F ~]$ suPassword: tonybash-3.2# passwd -d rootRemoving password for user root.passwd: Successbash-3.2# exit[olpc@xo-10-CC-6F ~]$
Now the problem is that there is no way to print stuff from any of the Sugar activities. The best place toput in print support would be the Journal
activity. Along the bottom where the mounted USB keys arelocated could be an icon for a printer, and dragging a file down to the printer ojbect could cause it tobe send to the printer.
The alternative is to write some scripts invocable from the Terminal activity to determine what isin the journal, and send them to LPR with the appropriate parameters.
I did not have time to do either of these, but perhaps someone out there can take on that as a project.
technorati tags: OLPC, XO, printing, printer, linux, Opera, Firefox, Java, Flash
Since so many personal and corporate users are still on [Windows XP], Microsoft announced that it would provide [Extended Support until 2014]. A ComputerWorld article back in 2007 offered tips on [How to make Windows XP last for the next seven years]. From May 2009 to April 2014, all support is fee-based and non-security hotfixes are produced only for corporate customers.
If we have learned anything from last decade's Y2K crisis, is that we should not wait for the last minute to take action. Now is the time to start thinking about weaning ourselves off Windows XP. IBM has 400,000 employees, so this is not a trivial matter.
Already, IBM has taken some bold steps:
Last July, IBM announced that it was switching from Internet Explorer (IE6) to [Mozilla Firefox as its standard browser]. IBM has been contributing to this open source project for years, including support for open standards, and to make it [more accessible to handicapped employees with visual and motor impairments]. I use Firefox already on Windows, Mac and Linux, so there was no learning curve for me. Before this announcement, if some web-based application did not work on Firefox, our Helpdesk told us to switch back to Internet Explorer. Those days are over. Now, if a web-based application doesn't work on Firefox, we either stop using it, or it gets fixed.
IBM also announced the latest [IBM Lotus Symphony 3] software, which replaces Microsoft Office for Powerpoint, Excel and Word applications. Symphony also works across Mac, Windows and Linux. It is based on the OpenOffice open source project, and handles open-standard document formats (ODF). Support for Microsoft Office 2003 will also run out in the year 2014, so moving off proprietary formats to open standards makes sense.
I am not going to wait for IBM to decide how to proceed next, so I am starting my own migrations. In my case, I need to do it twice, on my IBM-provided laptop as well as my personal PC at home.
- IBM-provided laptop
Last summer, IBM sent me a new laptop, we get a new one every 3-4 years. It was pre-installed with Windows XP, but powerful enough to run a 64-bit operating system in the future. Here are my series of blog posts on that:
I decided to try out Red Hat Enterprise Linux 6.1 with its KVM-based Red Hat Enterprise Virtualization to run Windows XP as a guest OS. I will try to run as much as I can on native Linux, but will have Windows XP guest as a next option, and if that still doesn't work, reboot the system in native Windows XP mode.
Here's is how I have configured my laptop:
|/dev/sda1||35GB||NTFS||C:||Windows XP SP3 operating system and programs|
|/dev/sda2||15GB||ext4||/(root)||Ubuntu Desktop 10.10, SystemRescueCD, Clonezilla, Parted Magic|
|/dev/sda3||55GB||ext4||/(root)||RHEL 6.1 with KVM to run Windows XP as guest OS|
|/dev/sda6||130GB||NTFS||D:||My Documents, Lotus Notes and other data|
|/dev/sda7||70GB||NTFS||E:||Extras and Archives|
Basically, this is a multi-boot system. I use Ubuntu to hold all my Linux utilities, including [SystemRescueCD], [Clonezilla], and [Parted Magic]. The new [Grub2 loader] makes this easy.
Here is what my initial boot screen looks like:
So far, I am pleased that I can do nearly everything my job requires natively in Red Hat Linux, including accessing my Lotus Notes for email and databases, edit and present documents with Lotus Symphony, and so on. I have made RHEL 6.1 my default when I boot up. Setting up Windows XP under KVM was relatively simple, involving an 8-line shell script and 54-line XML file. Here is what I have encountered:
- We use a wonderful tool called "iSpring Pro" which merges Powerpoint slides with voice recordings for each page into a Shockwave Flash video. I have not yet found a Linux equivalent for this yet.
- To avoid having to duplicate files between systems, I use instead symbolic links. For example, my Lotus Notes local email repository sits on D: drive, but I can access it directly with a link from /home/tpearson/notes/data.
- While my native Ubuntu and RHEL Linux can access my C:, D: and E: drives in native NTFS file system format, the irony is that my Windows XP guest OS under KVM cannot. This means moving something from NTFS over to Ext4, just so that I can access it from the Windows XP guest application.
- For whatever reason, "Password Safe" did not run on the Windows XP guest. I launch it, but it takes forever to load and never brings up the GUI. Fortunately, there is a Linux version [MyPasswordSafe] that seems to work just fine to keep track of all my passwords.
- Personal home PC
My Windows XP system at home gave up the ghost last month, so I bought a new system with Windows 7 Professional, quad-core Intel processor and 6GB of memory. There are [various editions of Windows 7], but I chose Windows 7 Professional to support running Windows XP as a guest image.
Here's is how I have configured my personal computer:
|/dev/sda1||104MB||NTFS||C:||Windows 7 Loader|
|/dev/sda2||10GB||ext4||/(root)||Ubuntu Desktop 10.10, SystemRescueCD, Clonezilla, Parted Magic|
|/dev/sda6||60GB||NTFS||C:||Windows 7 OS and programs|
|/dev/sda7||230GB||NTFS||D:||My Documents, Lotus Notes and other data|
|/dev/sda8||250GB||NTFS||E:||Extras and Archives|
I actually found it more time-consuming to implement the "Virtual PC" feature of Windows 7 to get Windows XP mode working than KVM on Red Hat Linux. I am amazed how many of my Windows XP programs DO NOT RUN AT ALL natively on Windows 7. I now have native 64-bit versions of Lotus Notes and Symphony 3, which will do well enough for me for now.
I went ahead and put Red Hat Linux on my home system as well, but since I have Windows XP running as a guest under Windows 7, no need to duplicate KVM setup there. At least if I have problems with Windows 7, I can reboot in RHEL6 Linux at home and use that for Linux-native applications.
Hopefully, this will position me well in case IBM decides to either go with Windows 7 or Linux as the replacement OS for Windows XP.
technorati tags: IBM, Windows, Windows XP, Windows 7, Linux, Ubuntu, RedHat, RHEL, RHEL6, Lotus, Lotus Notes, Lotus Symphony
Continuing my catch-up on past posts, Jon Toigo on his DrunkenData
blog, posted a ["bleg"
] for information aboutdeduplication. The responses come from the "who's who" of the storage industry, so I will provide IBM'sview. (Jon, as always, you have my permission to post this on your blog!)
- Please provide the name of your company and the de-dupe product(s) you sell. Please summarize what you think are the key values and differentiators of your wares.
IBM offers two different forms of deduplication. The first is IBM System Storage N series disk system with Advanced Single Instance Storage (A-SIS), and the second is IBM Diligent ProtecTier software. Larry Freeman from NetApp already explains A-SIS in the [comments on Jon's post], so I will focus on the Diligent offering in this post. The key differentiators for Diligent are:
- Data agnostic. Diligent does not require content-awareness, format-awareness nor identification of backup software used to send the data. No special client or agent software is required on servers sending data to an IBM Diligent deployment.
- Inline processing. Diligent does not require temporarily storing data on back-end disk to post-process later.
- Scalability. Up to 1PB of back-end disk managed with an in-memory dictionary.
- Data Integrity. All data is diff-compared for full 100 percent integrity. No data is accidentally discarded based on assumptions about the rarity of hash collisions.
- InfoPro has said that de-dupe is the number one technology that companies are seeking today — well ahead of even server or storage virtualization. Is there any appeal beyond squeezing more undifferentiated data into the storage junk drawer?
Diligent is focused on backup workloads, which has the best opportunity for deduplication benefits. The two main benefits are:
- Keeping more backup data available online for fast recovery.
- Mirroring the backup data to another remote location for added protection. With inline processing, only the deduplicated data is sent to the back-end disk, and this greatly reduces the amount of data sent over the wire to the remote location.
- Every vendor seems to have its own secret sauce de-dupe algorithm and implementation. One, Diligent Technologies (just acquired by IBM), claims that their’s is best because it collapses two functions — de-dupe then ingest — into one inline function, achieving great throughput in the process. What should be the gating factors in selecting the right de-dupe technology?
As with any storage offering, the three gating factors are typically:
- Will this meet my current business requirements?
- Will this meet my future requirements for the next 3-5 years that I plan to use this solution?
- What is the Total Cost of Ownership (TCO) for the next 3-5 years?
Assuming you already have backup software operational in your existing environment, it is possible to determine thenecessary ingest rate. How many "Terabytes per Hour" (TB/h) must be received, processed and stored from the backup software during the backup window. IBM intends to document its performance test results of specific software/hardwarecombinations to provide guidance to clients' purchase and planning decisions.
For post-process deployments, such as the IBM N series A-SIS feature, the "ingest rate" during the backup only has to receive and store the data, and the rest of the 24-hour period can be spent doing the post-processing to find duplicates. This might be fine now, but as your data grows, you might find your backup window growing, and that leaves less time for post-processing to catch up. IBM Diligent does the processing inline, so is unaffected by an expansion of the backup window.
IBM Diligent can scale up to 1PB of back-end data, and the ingest rate does not suffer as more data is managed.
As for TCO, post-process solutions must have additional back-end storage to temporarily hold the data until the duplicates can be found. With IBM Diligent's inline methodology, only deduplicated data is stored, so less disk space is required for the same workloads.
- Despite the nuances, it seems that all block level de-dupe technology does the same thing: removes bit string patterns and substitutes a stub. Is this technically accurate or does your product do things differently?
IBM Diligent emulates a tape library, so the incoming data appears as files to be written sequentially to tape. A file is a string of bytes. Unlike block-level algorithms that divide files up into fixed chunks, IBM Diligent performs diff-compares of incoming data with existing data, and identifies ranges of bytes that duplicate what already is stored on the back-end disk. The file is then a sequence of "extents" representing either unique data or existing data. The file is represented as a sequence of pointers to these extents. An extent can vary from2KB to 16MB in size.
- De-dupe is changing data. To return data to its original state (pre-de-dupe) seems to require access to the original algorithm plus stubs/pointers to bit patterns that have been removed to deflate data. If I am correct in this assumption, please explain how data recovery is accomplished if there is a disaster. Do I need to backup your wares and store them off site, or do I need another copy of your appliance or software at a recovery center?
For IBM Diligent, all of the data needed to reconstitute the data is stored on back-end disks. Assuming that all of your back-end disks are available after the disaster, either the original or mirrored copy, then you only need the IBM Diligent software to make sense of the bytes written to reconstitute the data. If the data was written by backup software, you would also need compatible backup software to recover the original data.
- De-dupe changes data. Is there any possibility that this will get me into trouble with the regulators or legal eagles when I respond to a subpoena or discovery request? Does de-dupe conflict with the non-repudiation requirements of certain laws?
I am not a lawyer, and certainly there are aspects of[non-repudiation] that may or may not apply to specific cases.
What I can say is that storage is expected to return back a "bit-perfect" copy of the data that was written. Thereare laws against changing the format. For example, an original document was in Microsoft Word format, but is converted and saved instead as an Adobe PDF file. In many conversions, it would be difficult to recreate the bit-perfect copy. Certainly, it would be difficult to recreate the bit-perfect MS Word format from a PDF file. Laws in France and Germany specifically require that the original bit-perfect format be kept.
Based on that, IBM Diligent is able to return a bit-perfect copy of what was written, same as if it were written to regular disk or tape storage, because all data is diff-compared byte-for-byte with existing data.
In contrast, other solutions based on hash codes have collisions that result in presenting a completely different set of data on retrieval. If the data you are trying to store happens to have the same hash code calculation as completely different data already stored on a solution, then it might just discard the new data as "duplicate". The chance for collisions might be rare, but could be enough to put doubt in the minds of a jury. For this reason, IBM N series A-SIS, that does perform hash code calculations, will do a full byte-for-byte comparison of data to ensure that data is indeed a duplicate of an existing block stored.
- Some say that de-dupe obviates the need for encryption. What do you think?
I disagree. I've been to enough [Black Hat] conferences to know that it would be possible to read thedata off the back-end disk, using a variety of forensic tools, and piece together strings of personal information,such as names, social security numbers, or bank account codes.
Currently, IBM provides encryption on real tape (both TS1120 and LTO-4 generation drives), and is working withopen industry standards bodies and disk drive module suppliers to bring similar technology to disk-based storage systems.Until then, clients concerned about encryption should consider OS-based or application-based encryption from thebackup software. IBM Tivoli Storage Manager (TSM), for example, can encrypt the data before sending it to the IBMDiligent offering, but this might reduce the number of duplicates found if different encryption keys are used.
- Some say that de-duped data is inappropriate for tape backup, that data should be re-inflated prior to write to tape. Yet, one vendor is planning to enable an “NDMP-like” tape backup around his de-dupe system at the request of his customers. Is this smart?
Re-constituting the data back to the original format on tape allows the original backup software to interpret the tape data directly to recover individual files. For example, IBM TSM software can write its primary backup copies to an IBM Diligent offering onsite, and have a "copy pool" on physical tape stored at a remote location. The physical tapes can be used for recovery without any IBM Diligent software in the event of a disaster. If the IBM Diligent back-end disk images are lost, corrupted, or destroyed, IBM TSM software can point to the "copy pool" and be fully operational. Individual files or servers could be restored from just a few of these tapes.
An NDMP-like tape backup of a deduplicated back-end disk would require that all the tapes are in-tact, available, and fully restored to new back-end disk before the deduplication software could do anything. If a single cartridge fromthis set was unreadable or misplaced, it might impact the access to many TBs of data, or render the entire systemunusable.
In the case of a 1PB of back-end disk for IBM Diligent, you would be having to recover over a thousand tapes back to disk before you could recover any individual data from your backup software. Even with dozens of tape drives in parallel, could take you several days for the complete process.This represents a longer "Recovery Time Objective" (RTO) than most people are willing to accept.
- Some vendors are claiming de-dupe is “green” — do you see it as such?
Certainly, "deduplicated disk" is greener than "non-deduplicated" disk, but I have argued in past posts, supportedby Analyst reports, that it is not as green as storing the same data on "non-deduplicated" physical tape.
- De-dupe and VTL seem to be joined at the hip in a lot of vendor discussions: Use de-dupe to store a lot of archival data on line in less space for fast retrieval in the event of the accidental loss of files or data sets on primary storage. Are there other applications for de-duplication besides compressing data in a nearline storage repository?
Deduplication can be applied to primary data, as in the case of the IBM System Storage N series A-SIS. As Larrysuggests, MS Exchange and SharePoint could be good use cases that represent the possible savings for squeezing outduplicates. On the mainframe, many master-in/master-out tape applications could also benefit from deduplication.
I do not believe that deduplication products will run efficiently with “update in place” applications, that is high levels of random writes for non-appending updates. OLTP and Database workloads would not benefit from deduplication.
- Just suggested by a reader: What do you see as the advantages/disadvantages of software based deduplication vs. hardware (chip-based) deduplication? Will this be a differentiating feature in the future… especially now that Hifn is pushing their Compression/DeDupe card to OEMs?
In general, new technologies are introduced on software first, and then as implementations mature, get hardware-based to improve performance. The same was true for RAID, compression, encryption, etc. The Hifn card does "hash code" calculations that do not benefit the current IBM Diligent implementation. Currently, IBM Diligent performsLZH compression through software, but certainly IBM could provide hardware-based compression with an integrated hardware/software offering in the future. Since IBM Diligent's inline process is so efficient, the bottleneck in performance is often the speed of the back-end disk. IBM Diligent can get improved "ingest rate" using FC instead of SATA disk.
Sorry, Jon, that it took so long to get back to you on this, but since IBM had just acquired Diligent when you posted, it took me a while to investigate and research all the answers.
technorati tags: IBM, Diligent, Jon Toigo, DrunkenData, bleg, deduplication, A-SIS, NetApp, ProtecTier, inline, post-process, back-end, disk, data integrity, hash, collision, ingest rate, VTL, non-repudiation, extent, bit-perfect, Microsoft Word, Adobe PDF, diff, Black Hat, encryption, compression, Hifn, FC, SATA