This blog is for the open exchange of ideas relating to IBM Systems, storage and storage networking hardware, software and services.
(Short URL for this blog: ibm.co/Pearson )
Tony Pearson is a Master Inventor, Senior IT Architect and Event Content Manager for [IBM Systems for IBM Systems Technical University] events. With over 30 years with IBM Systems, Tony is frequent traveler, speaking to clients at events throughout the world.
Lloyd Dean is an IBM Senior Certified Executive IT Architect in Infrastructure Architecture. Lloyd has held numerous senior technical roles at IBM during his 19 plus years at IBM. Lloyd most recently has been leading efforts across the Communication/CSI Market as a senior Storage Solution Architect/CTS covering the Kansas City territory. In prior years Lloyd supported the industry accounts as a Storage Solution architect and prior to that as a Storage Software Solutions specialist during his time in the ATS organization.
Lloyd currently supports North America storage sales teams in his Storage Software Solution Architecture SME role in the Washington Systems Center team. His current focus is with IBM Cloud Private and he will be delivering and supporting sessions at Think2019, and Storage Technical University on the Value of IBM storage in this high value IBM solution a part of the IBM Cloud strategy. Lloyd maintains a Subject Matter Expert status across the IBM Spectrum Storage Software solutions. You can follow Lloyd on Twitter @ldean0558 and LinkedIn Lloyd Dean.
Tony Pearson's books are available on Lulu.com! Order your copies today!
Safe Harbor Statement: The information on IBM products is intended to outline IBM's general product direction and it should not be relied on in making a purchasing decision. The information on the new products is for informational purposes only and may not be incorporated into any contract. The information on IBM products is not a commitment, promise, or legal obligation to deliver any material, code, or functionality. The development, release, and timing of any features or functionality described for IBM products remains at IBM's sole discretion.
Tony Pearson is a an active participant in local, regional, and industry-specific interests, and does not receive any special payments to mention them on this blog.
Tony Pearson receives part of the revenue proceeds from sales of books he has authored listed in the side panel.
Tony Pearson is not a medical doctor, and this blog does not reference any IBM product or service that is intended for use in the diagnosis, treatment, cure, prevention or monitoring of a disease or medical condition, unless otherwise specified on individual posts.
The developerWorks Connections platform will be sunset on December 31, 2019. On January 1, 2020, this blog will no longer be available. More details available on our FAQ.
(Note: The following paragraphs have been updated to clarify the performance tests involved.)
This time, IBM breaks the 1 million IOPS barrier, achieved by running a test workload consisting of a 70/30 mix of random 4K requests. That is 70 percent reads, 30 percent writes, with 4KB blocks. The throughput achieved was 3.5x times that obtained by running the identical workload on the fastest IBM storage system today (IBM System Storage SAN Volume Controller 4.3),
and an estimated EIGHT* times the performance of EMC DMX. With an average response time under 1 millisecond, this solution would be ideal for online transaction processing (OLTP) such as financial recordings or airline reservations.
(*)Note: EMC has not yet published ANY benchmarks of their EMC DMX box with SSD enterprise flash drives (EFD). However, I believe that the performance bottleneck is in their controller and not the back-end SSD or FC HDD media, so I have givenEMC the benefit of the doubt and estimated that their latest EMC DMX4 is as fast as an[IBMDS8300 Turbo] with Fibre Channel drives. If or when EMC publishes benchmarks, the marketplace can make more accurate comparisons. Your mileage may vary.
IBM used 4 TB of Solid State Disk (SSD) behind its IBM SAN Volume Controller (SVC) technology to achieve this amazing result. Not only does this represent a significantly smaller footprint, but it uses only 55 percent of the power and cooling.
The SSD drives are made by [Fusion IO] and are different than those used by EMC made by STEC.
The SVC addresses the one key problem clients face today with competitive disk systems that support SSD enterprise flash drives: choosing what data to park on those expensive drives? How do you decide which LUNs, which databases, or which files should be permanently resident on SSD? With SVC's industry-leading storage virtualization capability, you are not forced to decide. You can move data into SSD and back out again non-disruptively, as needed to meet performance requirements. This could be handy for quarter-end or year-end processing, for example.
Once again it's Tuesday, which means IBM announcement day!
Today IBM announced [two new DS3400 SAN Express Models]. These two new models will replace the IBM System Storage DS3400 SAN Express Kit model 41U and 42U to be withdrawn from marketing today. The DS3000 series of scalable, flexible, and affordable storage solutions support IBM System x, System p, and BladeCenter servers.
Two new IBM System Storage DS3400 SAN Express Kits are being introduced that provide the parts needed to setup and configure a SAN with the exception of a SAN switch that can be ordered separately. The IBM System Storage DS3400 SAN Express Kits contain Emulex EZPilot software that enables automated installation and configuration of the SAN components. IBM System Storage DS3400 SAN Express Kits models 41S and 42S and Emulex EZPilot software work in conjunction with the IBM TotalStorage SAN16B-2 Express Model Switch which comes with eight ports and eight 4 Gbps SFPs. The EZPilot software can support configurations with either one or two SAN16B-2 switches.
The 41S is a single-controller model DS3400 with two HBA cards and four cables. The 42S is the dual-controller model with two HBA cards and eight cables.
"The murals in restaurants are on par with the food in museums." --- Peter De Vries
The quote above applies to blogs as well. Those about competitive products of which the blogger has little to no hands-on experience tend to be terribly misleading or technically inaccurate. We saw this last month as Sun Microsystems' Jeff Savit tried to discuss the IBM System z10 EC mainframe.
This time, it comes from EMC bloggers discussing NetApp equipment, and by association, IBM System Storage N series gear.I was going to comment on the ridiculous posts by fellow bloggers from EMC about SnapLock compliance feature on the NetApp, but my buddies at NetApp had already done this for me, saving me the trouble.
The hysterical nature of writing from EMC, and the calm responses from NetApp, speak volumes about the culturesof both companies.
The key point is that none of the "Non-erasable, Non-Rewriteable" (NENR) storage out there are certified as compliant by any government agency on the planet. Governments just aren't in the business of certifying such things. The best you can get is a third-party consultant, such as [Cohasset Associates], to help make decisions that are best for each particular situation.
In addition to SnapLock on N series, IBM offers the [IBM System Storage DR550], WORM tape and optical systems, all of which have been deemed compliant to the U.S. Securities and Exchange Commission [SEC 17a-4] federal regulations by Cohasset Associates. For medical patient records and images like X-rays, IBM offers the Grid Medical Archive Solution [GMAS]designed to meet the requirements of the U.S. Health Insurance Portability and Accountability Act[HIPAA].For other government or industry regulations, consult with your legal counsel.
Well, it's Tuesday, and so it is "announcement day" again! Actually, for me it is Wednesday morning herein Mumbai, India, but since I was "press embargoed" until 4pm EDT in talking about these enhancements, I had to wait until Wednesday morning here to talk about them.
World's Fastest 1TB tape drive
IBM announced its new enterprise [TS1130 tape drive]and corresponding [TS3500 tape library support]. This one has a funny back-story. Last week while we were preparing the Press Release, we debated on whether we should compare the 1TB per cartridge capacity as double that of Sun's Enterprise T10000 (500GB), or LTO-4 (800GB). The problem changed when Sun announced on Monday they too had a 1TB tape drive, so now instead ofsaying that we had the "World's First 1TB tape drive", we quickly changed this to the "World's Fastest 1TB tape drive" instead. At 160MB/sec top speed, IBM's TS1130 is 33 percent faster than Sun's latest announcement. Sun was rather vague when they will actually ship their new units, so IBM may still end up being first to deliver as well.
While EMC and other disk-only vendors have stopped claiming that "tape is dead", these recent announcements from IBM and Sun indicate that indeed tape is alive and well. IBM is able to borrow technologies from disk, such as the Giant Magneto Resistive (GMR) head over to its tape offerings, which means much of the R&D for disk applies to tape, keeping both forms ofstorage well invested. Tape continues to be the "greenest" storage option, more energy efficient than disk, optical, film, microfiche and even paper.
On the LTO front, IBM enhanced the reporting capabilities of its[TS3310] midrange tape library. This includes identifying the resource utilization of the drives, reporting on media integrity, and improved diagnostics to support library-managed encryption.
IBM System Storage DR550
As a blended disk-and-tape solution, the [IBM System Storage DR550] easily replaces the EMC Centera to meet compliance storagerequirements. IBM announced that we have greatly expanded its scalability, being able to support both 1TBdisk drives, as well as being able to attach to either IBM or Sun's 1TB tape drives.
Massive Array of Idle Disks (MAID)
IBM now offers a "Sleep Mode" in the firmware of the [IBM System Storage DCS9550], which is often called "Massive Array of Idle Disks" (MAID) or spin-down capability. This can reduce the amount of power consumed during idle times.
That's a lot of exciting stuff. I'm off to breakfast now.
Continuing my week in Tokyo, Japan, I was going to title this post "Chunks, Extents and Grains", but decidedinstead to use the fairy tale above.
Fellow blogger BarryB from EMC, on his The Storage Anarchist blog, once again shows off his [PhotoShop talents], in his post [the laurel and hardy of thin provisioning]. This time, BarryB depicts fellow blogger and IBM master inventor, Barry Whyte, as Stan Laurel and fellow blogger Hu Yoshida from HDS as Oliver Hardy.
At stake is the comparison in various implementations of thin provisioning among the major storage vendors.On the "thick end", Hu presents his case for 42MB chunks on his post [When is Thin Provisioning Too Thin]. On the "thin end", IBMer BarryW presents the "fine-grained" details of Space-efficient Volumes (SEV), made available with the IBM System Storage SAN Volume Controller (SVC) v4.3, in his series of posts:
BarryB paints both implementations as "extremes" in inefficiency. Some excerpts from his post:
"... Hitachi's "chubby" provisioning is probably more performance efficient with external storage than is the SVC's "thin" approach. But it is still horribly inefficient in context of capacity utilization.
... the "thin extent" size used by Symmetrix Virtual Provisioning is both larger than the largest that SVC uses, and (significantly) smaller than what Hitachi uses."
"free" may be the most expensive solution you can buy...
Before you rush off to put a bunch of SVCs running (free) SEV in front of your storage arrays, you might want to consider the performance implications of that choice. Likewise, for Hitachi's DP, you probably want to understand the impact on capacity utilization that DP will have. DP isn't free, and it isn't very space efficient, either."
BarryB would like you to think that since EMC has chosen an "extent" size between 257KB and 41MB it must therefore be the optimal setting, not too hot, and not too cold. As I mentioned last January in my post[DoesSize Really Matter for Performance?], EMC engineers had not yet decided what that extent size should be, andBarryB is noticeably vague on the current value.According to this [VMware whitepaper],the thin extent size is currently 768 KBin size. Future versions of the EMC Enginuity operating environment may change the thin extent size. (I am sure theEMC engineers are smarter and more decisive than BarryB would lead us to believe!)
BarryB is correct that any thin provisioning implementation is not "free", even though IBM's implementation is offeredat no additional charge. Some writes may be slowed downwaiting for additional storage to be allocated to satisfy the request, and some amount of storage must be set asideto hold the metadata directory to point to all these chunks, extents or grains. For the convenience of not havingto dynamically expand LUNs manually as more space is needed, you will pay both a performance and capacity "price".
However, as they say, the [proof of the pudding is in the eating], or perhaps I should say porridge in this case.Given that the DMX4 is slower than both HDS USP-V and IBM SVC, you won't see EMC publishing industry-standard[SPC benchmarks] using their"thin extent" implementation anytime soon. IBM allows a choice of grain size, from 32KB to 256KB, in an elegantdesign that keeps the metadata directory less than 0.1 to 0.5 percent overhead. I would be surprised if EMC canmake a case to be more efficient than that! The performance tests are stillbeing run, but what I have seen so far, people will be very pleased with the minimal impact from IBM SEV, an acceptable trade-off for improved utilization and reduced out-of-space conditions.
So if you are a client waiting for your EMC equipment to be fully depreciated so you can replace it for faster equipment from IBM or HDS, you can at least improveits performance and capacity utilization today by virtualizing it with IBM SAN Volume Controller.
Based on this success, and perhaps because I am also fluent in Spanish, I was asked to help with Proyecto Ceibal, the team for OLPC Uruguay. Normally theXS school server resides at the school location itself, so that even if the internet connection is disrupted or limited, the school kids can continue to access each other and the web cache content until internet connection is resumed.However, with a diverse developmentteam with people in United States, Uruguay, and India, we first looked to Linux hosting providers that wouldagree to provide free or low-cost monthly access. We spent (make that "wasted") the month of May investigating.Most that I talked to were not interested in having a customized Linux kernel on non-standard hardware on their shop floor, and wanted instead to offer their own standard Linux build on existing standard servers, managed by theirown system administrators, or were not interested in providing it for free. Since the XS-163 kernel is customizedfor the x86 architecture, it is one of those exceptions where we could not host it on an IBM POWER or mainframe as a virtual guest.
This got picked up as an [idea] for the Google's[Summer of Code] and we are mentoring Tarun, a 19-year-old student to actas lead software developer. However, summer was fast approaching, and we wanted this ready for the next semester. In June, our project leader, Greg, came up with a new plan. Build a machine and have it connected at an internet service provider that would cover the cost of bandwidth, and be willing to accept this with remote administration. We found a volunteer organization to cover this -- Thank you Glen and Vicki!
We found a location, so the request to me sounded simple enough: put together a PC from commodity parts that meet the requirements of the customizedLinux kernel, the latest release being called [XS-163]. The server would have two disk drives, three Ethernet ports, and 2GB of memory; and be installed with the customized XS-163 software, SSHD for remote administration, Apache web server, PostgreSQL database and PHP programming language.Of course, the team wanted this for as little cost as possible, and for me to document the process, so that it could be repeated elsewhere. Some stretch goals included having a dual-boot with Debian 4.0 Etch Linux for development/test purposes, an alternative database such as MySQL for testing, a backup procedure, and a Recover-DVD in case something goes wrong.
Some interesting things happened:
The XS-163 is shipped as an ISO file representing a LiveCD bootable Linux that will wipe your system cleanand lay down the exact customized software for a one-drive, three-Ethernet-port server. Since it is based on Red Hat's Fedora 7 Linux base, I found it helpful to install that instead, and experiment moving sections of code over.This is similar to geneticists extracting the DNA from the cell of a pit bull and putting it into the cell for a poodle. I would not recommend this for anyone not familiar with Linux.
I also experimented with modifying the pre-built XS-163 CD image by cracking open the squashfs, hacking thecontents, and then putting it back together and burning a new CD. This provided some interesting insight, but in the end was able to do it all from the standard XS-163 image.
Once I figured out the appropriate "scaffolding" required, I managed to proceed quickly, with running versionsof XS-163, plain vanilla Fedora 7, and Debian 4, in a multi-boot configuration.
The BIOS "raid" capability was really more like BIOS-assisted RAID for Windows operating system drivers. This"fake raid" wasn't supported by Linux, so I used Linux's built-in "software raid" instead, which allowed somepartitions to be raid-mirrored, and other partitions to be un-mirrored. Why not mirror everything? With two160GB SATA drives, you have three choices:
No RAID, for a total space of 320GB
RAID everything, for a total space of 160GB
Tiered information infrastructure, use RAID for some partitions, but not all.
The last approach made sense, as a lot of of the data is cache web page images, and is easily retrievable fromthe internet. This also allowed to have some "scratch space" for downloading large files and so on. For example,90GB mirrored that contained the OS images, settings and critical applications, and 70GB on each drive for scratchand web cache, results in a total of 230GB of disk space, which is 43 percent improvement over an all-RAID solution.
While [Linux LVM2] provides software-based "storage virtualization" similar to the hardware-based IBM System Storage SAN Volume Controller (SVC), it was a bad idea putting different "root" directories of my many OS images on there. With Linux, as with mostoperating systems, it expects things to be in the same place where it last shutdown, but in a multi-boot environment, you might boot the first OS, move things around, and then when you try to boot second OS, it doesn'twork anymore, or corrupts what it does find, or hangs with a "kernel panic". In the end, I decided to use RAIDnon-LVM partitions for the root directories, and only use LVM2 for data that is not needed at boot time.
While they are both Linux, Debian and Fedora were different enough to cause me headaches. Settings weredifferent, parameters were different, file directories were different. Not quite as religious as MacOS-versus-Windows,but you get the picture.
During this time, the facility was out getting a domain name, IP address, subnet mask and so on, so I testedwith my internal 192.168.x.y and figured I would change this to whatever it should be the day I shipped the unit.(I'll find out next week if that was the right approach!)
Afraid that something might go wrong while I am in Tokyo, Japan next week (July 7-11), or Mumbai, India the following week (July 14-18), I added a Secure Shell [SSH] daemon that runs automaticallyat boot time. This involves putting the public key on the server, and each remote admin has their own private key on their own client machine.I know all about public/private key pairs, as IBM is a leader in encryption technology, and was the first todeliver built-in encryption with the IBM System Storage TS1120 tape drive.
To have users have access to all their files from any OS image required that I either (a) have identical copieseverywhere, or (b) have a shared partition. The latter turned out to be the best choice, with an LVM2 logical volumefor "/home" directory that is shared among all of the OS images. As we develop the application, we might findother directories that make sense to share as well.
For developing across platforms, I wanted the Ethernet devices (eth0, eth1, and so on) match the actual ports they aresupposed to be connected to in a static IP configuration. Most people use DHCP so it doesn't matter, but the XSsoftware requires this, so it did. For example, "eth0" as the 1 Gbps port to the WAN, and "eth1/eth2" as the two 10/100 Mbps PCI NIC cards to other servers.Naming the internet interfaces to specific hardware ports wasdifferent on Fedora and Debian, but I got it working.
While it was a stretch goal to develop a backup method, one that could perform Bare Machine Recovery frommedia burned by the DVD, it turned out I needed to do this anyways just to prevent me from losing my work in case thingswent wrong. I used an external USB drive to develop the process, and got everything to fit onto a single 4GB DVD. Using IBM Tivoli Storage Manager (TSM) for this seemed overkill, and [Mondo Rescue] didn't handle LVM2+RAID as well as I wanted, so I chose [partimage] instead, which backs up each primary partition, mirrored partition, or LVM2 logical volume, keeping all the time stamps, ownerships, and symbolic links in tact. It has the ability to chop up the output into fixed sized pieces, which is helpful if you are goingto burn them on 700MB CDs or 4.7GB DVDs. In my case, my FAT32-formatted external USB disk drive can't handle files bigger than 2GB, so this feature was helpful for that as well. I standardized to 660 GiB [about 692GB] per piece, sincethat met all criteria.
The folks at [SysRescCD] saved the day. The standard "SysRescueCD" assigned eth0, eth1, and eth2 differently than the three base OS images, but the nice folks in France that write SysRescCD created a customized[kernel parameter that allowed the assignments to be fixed per MAC address ] in support of this project. With this in place, I was able to make a live Boot-CD that brings up SSH, with all the users, passwords,and Ethernet devices to match the hardware. Install this LiveCD as the "Rescue Image" on the hard disk itself, and also made a Recovery-DVD that boots up just like the Boot-CD, but contains the 4GB of backup files.
For testing, I used Linux's built-in Kernel-based Virtual Machine [KVM]which works like VMware, but is open source and included into the 2.6.20 kernels that I am using. IBM is the leadingreseller of Vmware and has been doing server virtualization for the past 40 years, so I am comfortable with thetechnology. The XS-163 platform with Apache and PostgreSQL servers as a platform for [Moodle], an open source class management system, and the combination is memory-intensive enough that I did not want to incur the overheads running production this manner, but it wasgreat for testing!
With all this in place, it is designed to not need a Linux system admin or XS-163/Moodle expert at the facility. Instead, all we need is someone to insert the Boot-CD or Recover-DVD and reboot the system if needed.
Just before packing up the unit for shipment, I changed the IP addresses to the values they need at the destination facility, updated the [GRUB boot loader] default, and made a final backup which burned the Recover-DVD. Hopefully, it works by just turning on the unit,[headless], without any keyboard, monitor or configuration required. Fingers crossed!
So, thanks to the rest of my team: Greg, Glen, Vicki, Tarun, Marcel, Pablo and Said. I am very excited to bepart of this, and look forward to seeing this become something remarkable!
Two weeks ago, I mentioned in my post [Pulse 2008 - Day 2 Breakout sessions] thatHenk de Ruiter from ABN Amro bank presented his success storyimplementing Information Lifecycle Management (ILM) across hisvarious data centers. I am no stranger to ABN Amro, having helped "ABN" and "Amro" banks merge their mainframe data in 1991. Henk has agreed to let me share with my readers more ofthis success story here on my blog:
Back in December 2005, Henkand his colleagues had come to visit the IBM Tucson ExecutiveBriefing Center (EBC) to hear about IBM products and services. At the time, I was part of our "STG Lab Services" team that performed ILM assessments at client locations. I explained to ABN Amro that the ILM methodology does not requirean all-IBM solution, and that ILM could even provide benefits with their current mix of storage, software and service providers.The ABN Amro team liked what I had to say, andmy team was commissioned to perform ILM assessments atthree of their data centers:
Sao Paulo (Brazil)
Chicago, IL (USA)
Each data center had its own management, its owndecision making, and its own set of issues, so we structuredeach ILM assessment independently. When we presented our results,we showed what each data center could do better with their existing mixed bagof storage, software and service providers, and also showed howmuch better their life would be with IBM storage, software andservices. They agreed to give IBM a chance to prove it, and soa new "Global Storage Study" was launched to take the recommendationsfrom our three ILM studies, and flesh out the details to make aglobally-integrated enterprise work for them. Once completed,it was renamed the "Global Storage Solution" (GSS).
Henk summarized the above with "I am glad to see Tony Pearsonin the audience, who was instrumental to making this all happen."As with many client testimonials, he presented a few charts onwho ABN Amro is today, the 12th largest bank worldwide, 8th largest in Europe. They operate in 53 countries and manage over a trillioneuros in assets.
They have over 20 data centers, with about 7 PB of disk, and over20 PB of tape, both growing at 50 to 70 percent CAGR. About 2/3 of theiroperations are now outsourced to IBM Global Services, the remaining 1/3is non-IBM equipment managed by a different service provider.
ABN Amro deployed IBM TotalStorage Productivity Center, variousIBM System Storage DS family disk systems, SAN Volume Controller (SVC), Tivoli StorageManager (TSM), Tivoli Provisioning Manager (TPM), and several other products. Armed with these products, they performed the following:
Clean Up. IBM uses the term "rationalization" to relate to the assignment of business value, to avoid confusion with theterm "classification" which many in IT relate to identifyingownership, read and write authorization levels. Often, in theinitial phases of an ILM deployment, a portion of the data isdetermined to be eligible for clean up, either to move to a lower-cost tier or deleted immediately. ABN Amro and IBM set a goal to identifyat least 20 percent of their data for clean up.
New tiers. Rather than traditional "storage tiers" which are often justTier 1 for Fibre Channel disk and Tier 2 for SATA disk, ABN Amroand IBM came up with seven "information infrastructure tiers" thatincorporate service levels, availability and protection status.They are:
High-performance, Highly-available disk with Remote replication.
High-performance, Highly-available disk (no remote replication)
Mid-performance, high-capacity disk with Remote replication
Mid-performance, high-capacity disk (no remote replication)
Non-erasable, Non-rewriteable (NENR) storage employinga blended disk and tape solution.
Enterprise Virtual Tape Library with remote replicationand back-end physical tape
Mid-performance physical tape
These tiers are applied equally across their mainframe anddistributed platforms. All of the tiers are priced per "primary GB", so any additional capacity required for replication orpoint-in-time copies, either local or remote, are all folded into the base price.ABN Amro felt a mission-critical applicationon Windows or UNIX deserves the same Tier 1 service level asa mission-critical mainframe application. Exactly!
Deployed storage virtualization for disk and tape. Thisinvolved the SAN Volume Controller and IBM TS7000 series library.
Implemented workflow automation. The key product here is IBM Tivoli Provisioning Manager
Started an investigation for HSM on distributed. This would be policy-based space management to migrate lessfrequently accessed data to the TSM pool for Windows or UNIX data.
While the deployment is not yet complete, ABN Amro feels they have alreadyrecognized business value:
Reduced cost by identifying data that should be stored on lower tiers
Simplified management, consolidated across all operating systems (mainframe, UNIX, Windows)
Increased utilization of existing storage resources
Reduced manual effort through policy-based automation, which can lead to fewer human errors and faster adaptability to new business opportunities
Standardized backup and other operational procedures
Henk and the rest of ABN Amro are quite pleased with the progress so far,although recent developments in terms of the takeover of ABN AMRO by aconsortium of banks means that the model is only implemented so far in Europe. Further rollout depends on the storage strategy of the new owners. Nonetheless,I am glad that I was able to work with Henk, Jason, Barbara, Steve, Tom, Dennis, Craig and othersto be part of this from the beginning and be able to see it rollout successfully over the years.
IBM is hosting a webcast about storage for SAP Environments. Learn how integrated IBM infrastructure solutions, specifically, customized for your SAP environments, can help lower your business costs, increases productivity in SAP development and test tasks, and improve resource utilization. This will include discussion of archive solutions with WebDAV, ArchiveLink and DR550;IBM Business Intelligence (BI) Accelerator; IBM support for SAP [Adaptive Computing]; and performance benchmark results. The session is intended for SAP and storage administrators, IT directorsand managers.
Here are the details:
Date: Wednesday, June 18, 2008
Time: 11:00am EDT (8:00am for those of us in Arizona or California)
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.