Tony Pearson is a Master Inventor and Senior IT Architect for the IBM Storage product line at the
IBM Executive Briefing Center in Tucson Arizona, and featured contributor
to IBM's developerWorks. In 2016, Tony celebrates his 30th year anniversary with IBM Storage. He is
author of the Inside System Storage series of books. This blog is for the open exchange of ideas relating to storage and storage networking hardware, software and services.
(Short URL for this blog: ibm.co/Pearson )
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Have you ever noticed that sometimes two movies come out that seem eerily similar to each other, released by different studios within months or weeks of each other? My sister used to review film scripts for a living, she would read ten of them and have to pick her top three favorites, and tells me that scripts for nearly identical concepts came all the time. Here are a few of my favorite examples:
1994: [Wyatt Earp] and [Tombstone] were Westerns recounting the famed gunfight at the O.K. Corral. Tombstone, Arizona is near Tucson, and the gunfight is recreated fairly often for tourists.
1998: [Armageddon] and [Deep Impact] were a pair of disaster movies dealing with a large rock heading to destroy all life on earth. I was in Mazatlan, Mexico to see the latter, dubbed in Spanish as "Impacto Profundo".
1998: [A Bug's Life] and [Antz] were computer-animated tales of the struggle of one individual ant in an ant colony.
2000: [Mission to Mars] and [Red Planet] were sci-fi pics exploring what a manned mission to our neighboring planet might entail.
This is different than copy-cat movies that are re-made or re-imagined many years later based on the previous successes of an original. Ever since my blog post [VPLEX: EMC's Latest Wheel is Round] in 2010 comparing EMC's copy-cat product that came our seven years after IBM's SAN Volume Controller (SVC), I've noticed EMC doesn't talk about VPLEX that much anymore.
This week, IBM announced [XIV Gen3 Solid-State Drive support] and our friends over at EMC announced [VFCache SSD-based PCIe cards]. Neither of these should be a surprise to anyone who follows the IT industry, as IBM had announced its XIV Gen3 as "SSD-Ready" last year specifically for this purpose, and EMC has been touting its "Project Lightning" since last May.
Fellow blogger Chuck Hollis from EMC has a blog post [VFCache means Very Fast Cache indeed] that provides additional detail. Chuck claims the VFCache is faster than popular [Fusion-IO PCIe cards] available for IBM servers. I haven't seen the performance spec sheets, but typically SSD is four to five times slower than the DRAM cache used in the XIV Gen3. The VFCache's SSD is probably similar in performance to the SSD supported in the IBM XIV Gen3, DS8000, DS5000, SVC, N series, and Storwize V7000 disk systems.
Nonetheless, I've been asked my opinions on the comparison between these two announcements, as they both deal with improving application performance through the use of Solid-State Drives as an added layer of read cache.
(FTC Disclosure: I am both a full-time employee and stockholder of the IBM Corporation. The U.S. Federal Trade Commission may consider this blog post as a paid celebrity endorsement of IBM servers and storage systems. This blog post is based on my interpretation and opinions of publicly-available information, as I have no hands-on access to any of these third-party PCIe cards. I have no financial interest in EMC, Fusion-IO, Texas Memory Systems, or any other third party vendor of PCIe cards designed to fit inside IBM servers, and I have not been paid by anyone to mention their name, brands or products on this blog post.)
The solutions are different in that IBM XIV Gen3 the SSD is "storage-side" in the external storage device, and EMC VFCache is "server-side" as a PCI Express [PCIe] card. Aside from that, both implement SSD as an additional read cache layer in front of spinning disk to boost performance. Neither is an industry first, as IBM has offered server-side SSD since 2007, and IBM and EMC have offered storage-side SSD in many of their other external storage devices. The use of SSD as read cache has already been available in IBM N series using [Performance Accelerator Module (PAM)] cards.
IBM has offered cooperative caching synergy between its servers and its storage arrays for some time now. The predecessor to today's POWER7-based were the iSeries i5 servers that used PCI-X IOP cards with cache to connect i5/OS applications to IBM's external disk and tape systems. To compete in this space, EMC created their own PCI-X cards to attach their own disk systems. In 2006, IBM did the right thing for our clients and fostered competition by entering in a [Landmark agreement] with EMC to [license the i5 interfaces]. Today, VIOS on IBM POWER systems allows a much broader choice of disk options for IBM i clients, including the IBM SVC, Storwize V7000 and XIV storage systems.
Can a little SSD really help performance? Yes! An IBM client running a [DB2 Universal Database] cluster across eight System x servers was able to replace an 800-drive EMC Symmetrix by putting eight SSD Fusion-IO cards in each server, for a total of 64 Solid-State drives, saving money and improving performance. DB2 has the Data Partitioning Feature that has multi-system DB2 configurations using a Grid-like architecture similar to how XIV is designed. Most IBM System x and BladeCenter servers support internal SSD storage options, and many offer PCIe slots for third-party SSD cards. Sadly, you can't do this with a VFCache card, since you can have only one VFCache card in each server, the data is unprotected, and only for ephemeral data like transaction logs or other temporary data. With multiple Fusion-IO cards in an IBM server, you can configure a RAID rank across the SSD, and use it for persistent storage like DB2 databases.
Here then is my side-by-side comparison:
IBM XIV Gen3 SSD Caching
Selected x86-based models of Cisco UCS, Dell PowerEdge, HP ProLiant DL, and IBM xSeries and System x servers
All of these, plus any other blade or rack-optimized server currently supported by XIV Gen3, including Oracle SPARC, HP Titanium, IBM POWER systems, and even IBM System z mainframes running Linux
Operating System support
Linux RHEL 5.6 and 5.7, VMware vSphere 4.1 and 5.0, and Windows 2008 x64 and R2.
All of these, plus all the other operating systems supported by XIV Gen3, including AIX, IBM i, Solaris, HP-UX, and Mac OS X
FCP and iSCSI
Vendor-supplied driver required on the server
Yes, the VFCache driver must be installed to use this feature.
No, IBM XIV Gen3 uses native OS-based multi-pathing drivers.
External disk storage systems required
None, it appears the VFCache has no direct interaction with the back-end disk array, so in theory the benefits are the same whether you use this VFCache card in front of EMC storage or IBM storage
XIV Gen3 is required, as the SSD slots are not available on older models of IBM XIV.
Shared disk support
No, VFCache has to be disabled and removed for vMotion to take place.
Yes! XIV Gen3 SSD caching shared disk supports VMware vMotion and Live Partition Mobility.
Support for multiple servers
An advantage of the XIV Gen3 SSD caching approach is that the cache can be dynamically allocated to the busiest data from any server or servers.
Support for active/active server clusters
Aware of changes made to back-end disk
No, it appears the VFCache has no direct interaction with the back-end disk array, so any changes to the data on the box itself are not communicated back to the VFCache card itself to invalidate the cache contents.
None identified. However, VFCache only caches blocks 64KB or smaller, so any sequential processing with larger blocks will bypass the VFCache.
Yes! XIV algorithms detect sequential access and avoid polluting the SSD with these blocks of data.
Number of SSD supported
One, which seems odd as IBM supports multiple Fusion-IO cards for its servers. However, this is not really a single point of failure (SPOF) as an application experiencing a VFCache failure merely drops down to external disk array speed, no data is lost since it is only read cache.
6 to 15 (one per XIV module) for high availability.
Pin data in SSD cache
Yes, using split-card mode, you can designate a portion of the 300GB to serve as Direct-attached storage (DAS). All data written to the DAS portion will be kept in SSD. However, since only one card is supported per server and the data is unprotected, this should only be used for ephemeral data like logs and temp files.
No, there is no option to designate an XIV Gen3 volume to be SSD-only. Consider using Fusion-IO PCIe card as a DAS alternative, or another IBM storage system for that requirement.
Pre-sales Estimating tools
Yes! CDF and Disk Magic tools are available to help cost-justify the purchase of SSD based on workload performance analysis.
IBM has the advantage that it designs and manufactures both servers and storage, and can design optimal solutions for our clients in that regard.
Well, it's Tuesday again, but this time, today we had our third big storage launch of 2009! A lot got announced today as part of IBM's big "Dynamic Infrastructure" marketing campaign. I will just focus on the
disk-related announcements today:
IBM System Storage DS8700
IBM adds a new model to its DS8000 series with the
[IBM System Storage DS8700]. Earlier this month, fellow blogger and arch-nemesis Barry Burke from EMC posted [R.I.P DS8300] on this mistaken assumption that the new DS8700 meant that DS8300 was going away, or that anyone who bought a DS8300 recently would be out of luck. Obviously, I could not respond until today's announcement, as the last thing I want to do is lose my job disclosing confidential information. BarryB is wrong on both counts:
IBM will continue to sell the DS8100 and DS8300, in addition to the new DS8700.
Clients can upgrade their existing DS8100 or DS8300 systems to DS8700.
BarryB's latest post [What's In a Name - DS8700] is fair game, given all the fun and ridicule everyone had at his expense over EMC's "V-Max" name.
So the DS8700 is new hardware with only 4 percent new software. On the hardware side, it uses faster POWER6 processors instead of POWER5+, has faster PCI-e buses instead of the RIO-G loops, and faster four-port device adapters (DAs) for added bandwidth between cache and drives. The DS8700 can be ordered as a single-frame dual 2-way that supports up to 128 drives and 128GB of cache, or as a dual 4-way, consisting of one primary frame, and up to four expansion frames, with up to 384GB of cache and 1024 drives.
Not mentioned explicitly in the announcements were the things the DS8700 does not support:
ESCON attachment - Now that FICON is well-established for the mainframe market, there is no need to support the slower, bulkier ESCON options. This greatly reduced testing effort. The 2-way DS8700 can support up to 16 four-port FICON/FCP host adapters, and the 4-way can support up to 32 host adapters, for a maximum of 128 ports. The FICON/FCP host adapter ports can auto-negotiate between 4Gbps, 2Gbps and 1Gbps as needed.
LPAR mode - When IBM and HDS introduced LPAR mode back in 2004, it sounded like a great idea the engineers came up with. Most other major vendors followed our lead to offer similar "partitioning". However, it turned out to be what we call in the storage biz a "selling apple" not a "buying apple". In other words, something the salesman can offer as a differentiating feature, but that few clients actually use. It turned out that supporting both LPAR and non-LPAR modes merely doubled the testing effort, so IBM got rid of it for the DS8700.
Update: I have been reminded that both IBM and HDS delivered LPAR mode within a month of each other back in 2004, so it was wrong for me to imply that HDS followed IBM's lead when obviously development happened in both companies for the most part concurrently prior to that. EMC was late to the "partition" party, but who's keeping track?
Initial performance tests show up to 50 percent improvement for random workloads, and up to 150 percent improvement for sequential workloads, and up to 60 percent improvement in background data movement for FlashCopy functions. The results varied slightly between Fixed Block (FB) LUNs and Count-Key-Data (CKD) volumes, and I hope to see some SPC-1 and SPC-2 benchmark numbers published soon.
The DS8700 is compatible for Metro Mirror, Global Mirror, and Metro/Global Mirror with the rest of the DS8000 series, as well as the ESS model 750, ESS model 800 and DS6000 series.
New 600GB FC and FDE drives
IBM now offers [600GB drives] for the DS4700 and DS5020 disk systems, as well as the EXP520 and EXP810 expansion drawers. In each case, we are able to pack up to 16 drives into a 3U enclosure.
Personally, I think the DS5020 should have been given a DS4xxx designation, as it resembles the DS4700
more than the other models of the DS5000 series. Back in 2006-2007, I was the marketing strategist for IBM System Storage product line, and part of my job involved all of the meetings to name or rename products. Mostly I gave reasons why products should NOT be renamed, and why it was important to name the products correctly at the beginning.
IBM System Storage SAN Volume Controller hardware and software
Fellow IBM master inventory Barry Whyte has been covering the latest on the [SVC 2145-CF8 hardware]. IBM put out a press release last week on this, and today is the formal announcement with prices and details. Barry's latest post
[SVC CF8 hardware and SSD in depth] covers just part of the entire
The other part of the announcement was the [SVC 5.1 software] which can be loaded
on earlier SVC models 8F2, 8F4, and 8G4 to gain better performance and functionality.
To avoid confusion on what is hardware machine type/model (2145-CF8 or 2145-8A4) and what is software program (5639-VC5 or 5639-VW2), IBM has introduced two new [Solution Offering Identifiers]:
5465-028 Standard SAN Volume Controller
5465-029 Entry Edition SAN Volume Controller
The latter is designed for smaller deployments, supports only a single SVC node-pair managing up to
150 disk drives, available in Raven Black or Flamingo Pink.
EXN3000 and EXP5060 Expansion Drawers
IBM offers the [EXN3000 for the IBM N series]. These expansion drawers can pack 24 drives in a 4U enclosure. The drives can either be all-SAS, or all-SATA, supporting 300GB, 450GB, 500GB and 1TB size capacity drives.
The [EXP5060 for the IBM DS5000 series] is a high-density expansion drawer that can pack up to 60 drives into a 4U enclosure. A DS5100 or DS5300
can handle up to eight of these expansion drawers, for a total of 480 drives.
Pre-installed with Tivoli Storage Productivity Center Basic Edition. Basic Edition can be upgraded with license keys to support Data, Disk and Standard Edition to extend support and functionality to report and manage XIV, N series, and non-IBM disk systems.
Pre-installed with Tivoli Key Lifecycle Manager (TKLM). This can be used to manage the Full Disk Encryption (FDE) encryption-capable disk drives in the DS8000 and DS5000, as well as LTO and TS1100 series tape drives.
IBM Tivoli Storage FlashCopy Manager v2.1
The [IBM Tivoli Storage FlashCopy Manager V2.1] replaces two products in one. IBM used
to offer IBM Tivoli Storage Manager for Copy Services (TSM for CS) that protected Windows application data, and IBM Tivoli Storage Manager for Advanced Copy Services (TSM for ACS) that protected AIX application data.
The new product has some excellent advantages. FlashCopy Manager offers application-aware backup of LUNs containing SAP, Oracle, DB2, SQL server and Microsoft Exchange data. It can support IBM DS8000, SVC and XIV point-in-time copy functions, as well as the Volume Shadow Copy Services (VSS) interfaces of the IBM DS5000, DS4000 and DS3000 series disk systems. It is priced by the amount of TB you copy, not on the speed or number of CPU processors inside the server.
Don't let the name fool you. IBM FlashCopy Manager does not require that you use Tivoli Storage Manager (TSM) as your backup product. You can run IBM FlashCopy Manager on its own, and it will manage your FlashCopy target versions on disk, and these can be backed up to tape or another disk using any backup product. However, if you are lucky enough to also be using TSM, then there is optional integration that allows TSM to manage the target copies, move them to tape, inventory them in its DB2 database, and provide complete reporting.
Yup, that's a lot to announce in one day. And this was just the disk-related portion of the launch!
From New York, Rolf went to London, Paris, Madrid, Morocco, Cairo, South Africa, Bangkok Thailand, Malaysia, Singapore, New Zealand, Australia, and then back to United States. I was hoping to run into him while I was in Australia and New Zealand last month, but our schedules did not line up.
Travelingwithout baggage is more than just a convenience, it is a metaphor for the philosophy that we should keep only what we need, and leave behind what we don't. This was the approach taken by IBM in the design of the IBM Storwize V7000 midrange disk system.
The IBM Storwize V7000 disk system consists of 2U enclosures. Controller enclosures have dual-controllers and drives. Expansion enclosures have just drives. Enclosures can have either 24 smaller form factor (SFF) 2.5-inch drives, or twelve larger 3.5-inch drives. A controller enclosure can be connected up to nine expansion enclosures.
The drives are all connected via 6 Gbps SAS, and come in a variety of speeds and sizes: 300GB Solid-State Drive (SSD); 300GB/450GB/600GB high-speed 10K RPM; and 2TB low-speed 7200 RPM drives. The 12-bay enclosures can be intermixed with 24-bay enclosures on the same system, and within an enclosure different speeds and sizes can be intermixed. A half-rack system (20U) could hold as much as 480TB of raw disk capacity.
This new system, freshly designed entirely within IBM, competes directly against systems that carry a lot of baggage, including the HDS AMS, HP EVA, an EMC CLARiiON CX4 systems. Instead, we decided to keep the what we wanted from our other successful IBM products.
Inspired by our successful XIV storage system, IBM has developed a web-based GUI that focuses on ease-of-use. This GUI uses the latest HTML5 and dojo widgets to provide an incredible user experience.
Borrowed from our IBM DS8000 high-end disk systems, state-of-the-art device adapters provide 6 Gbps SAS connectivity with a variety of RAID levels: 0, 1, 5, 6, and 10.
From our SAN Volume Controller, the embedded [ SVC 6.1 firmware] provides all of the features and functions normally associated with enterprise-class systems, including Easy Tier sub-LUN automated tiering between Solid-State Drives and Spinning disk, thin provisioning, external disk virtualization, point-in-time FlashCopy, disk mirroring, built-in migration capability, and long-distance synchronous and asynchronous replication.
Finally, the various "internal NDA" that kept me from publishing this sooner have expired, so now I have the long-awaited [Inside System Storage: Volume II], documenting IBM's transformation in its storage strategy, including behind-the-scenes commentary about IBM's acquisitions of XIV and Diligent. Available initially in paperback form. I am still working on the hard cover and eBook editions.
For those who have not yet read my first book, Inside System Storage: Volume I, it is still available from my publisher Lulu, in [hard cover], [paperback] and [eBook] editions.
IBM System Storage DS8800
A lesson IBM learned long ago was not to make radical changes to high-end disk systems, as clients who run mission-critical applications are more concerned about reliability, availability and serviceability than they are performance or functionality. Shipping any product before it was ready meant painfully having to fix the problems in the field instead.
(EMC apparently is learning this same lesson now with their VMAX disk system. Their Engenuity code from Symmetrix DMX4 was ported over to new CLARiiON-based hardware. With several hundred boxes in the field, they have already racked up over 150 severity 1 problems, roughly half of these resulted in data loss or unavailability issues. For the sake of our mutual clients that have both IBM servers and EMC disk, I hope they get their act together soon.)
To avoid this, IBM made incremental changes to the successful design and architecture of its predecessors. The new DS8800 shares 85 percent of the stable microcode from the DS8700 system. Functions like Metro Mirror, Global Mirror, and Metro/Global Mirror, are compatible with all of the previous models of the DS8000 series, as well as previous models of the IBM Enterprise Storage Server (ESS) line.
The previous models of DS8000 series were designed to take in cold air from both front and back, and route the hot air out the top, known as chimney design. However, many companies are re-arranging their data centers into separate cold aisles and hot aisles. The new DS8800 has front-to-back cooling to help accommodate this design.
My colleague Curtis Neal would call the rest of this a "BFD" announcement, which of course stands for "Bigger, Faster and Denser". The new DS8800 scales-up to more drives than its DS8700 predecessor, and can scale-out from a single-frame 2-way system to a multi-frame 4-way system. IBM has upgraded to faster 5GHz POWER6+ processors, with dual-core 8 Gbps FC and FICON host adapters, 8 Gbps device adapters, and 6 Gbps SAS connectivity to smaller form factor (SFF) 2.5-inch SAS drives. IBM Easy Tier will provide sub-LUN automated tiering between Solid-State Drives and spinning disk. The denser packaging with SFF drives means that we can pack over 1000 drives in only three frames, compared to five frames required for the DS8700.
The [IBM System Storage SAN Volume Controller] software release v6.1 brings Easy Tier sub-LUN automated tiering to the rest of the world. IBM Easy Tier moves the hottest, most active extents up to Solid-State Drives (SSD) and moves the coldest, least active down to spinning disk. This works whether the SSD is inside the SVC 2145-CF8 nodes, or in the managed disk pool.
Tired of waiting for EMC to finally deliver FAST v2 for your VMAX? It has been 18 months since they first announced that someday they would have sub-LUN automatic tiering. What is taking them so long? Why not virtualize your VMAX with SVC, and you can have it sooner!
SVC 6.1 also upgrades to a sexy new web-based GUI, which like the one for the IBM Storwize V7000, is based on the latest HTML5 and dojo widget standards. Inspired by the popular GUI from the IBM XIV Storage System, this GUI has greatly improved ease-of-use.
Here I am, day 11 of a 17-day business trip, on my last leg of the trip this week, in Kuala Lumpur in Malaysia. I have been flooded with requests to give my take on EMC's latest re-interpretation of storage virtualization, VPLEX.
I'll leave it to my fellow IBM master inventor Barry Whyte to cover the detailed technical side-by-side comparison. Instead, I will focus on the business side of things, using Simon Sinek's Why-How-What sequence. Here is a [TED video] from Garr Reynold's post
[The importance of starting from Why].
Let's start with the problem we are trying to solve.
Problem: migration from old gear to new gear, old technology to new technology, from one vendor to another vendor, is disruptive, time-consuming and painful.
Given that IT storage is typically replaced every 3-5 years, then pretty much every company with an internal IT department has this problem, the exception being those companies that don't last that long, and those that use public cloud solutions. IT storage can be expensive, so companies would like their new purchases to be fully utilized on day 1, and be completely empty on day 1500 when the lease expires. I have spoken to clients who have spent 6-9 months planning for the replacement or removal of a storage array.
A solution to make the data migration non-disruptive would benefit the clients (make it easier for their IT staff to keep their data center modern and current) as well as the vendors (reduce the obstacle of selling and deploying new features and functions). Storage virtualization can be employed to help solve this problem. I define virtualization as "technology that makes one set of resources look and feel like a different set of resources, preferably with more desirable characteristics.". By making different storage resources, old and new, look and feel like a single type of resource, migration can be performed without disrupting applications.
Before VPLEX, here is a breakdown of each solution:
Non-disruptive tech refresh, and a unified platform to provide management and functionality across heterogeneous storage.
Non-disruptive tech refresh, and a unified platform to provide management and functionality between internal tier-1 HDS storage, and external tier-2 heterogeneous storage.
Non-disruptive tech refresh, with unified multi-pathing driver that allows host attachment of heterogeneous storage.
New in-band storage virtualization device
Add in-band storage virtualization to existing storage array
New out-of-band storage virtualization device with new "smart" SAN switches
SAN Volume Controller
HDS USP-V and USP-VM
For IBM, the motivation was clear: Protect customers existing investment in older storage arrays and introduce new IBM storage with a solution that allows both to be managed with a single set of interfaces and provide a common set of functionality, improving capacity utilization and availability. IBM SAN Volume Controller eliminated vendor lock-in, providing clients choice in multi-pathing driver, and allowing any-to-any migration and copy services. For example, IBM SVC can be used to help migrate data from an old HDS USP-V to a new HDS USP-V.
With EMC, however, the motivation appeared to protect software revenues from their PowerPath multi-pathing driver, TimeFinder and SRDF copy services. Back in 2005, when EMC Invista was first announced, these three software represented 60 percent of EMC's bottom-line profit. (Ok, I made that last part up, but you get my point! EMC charges a lot for these.)
Back in 2006, fellow blogger Chuck Hollis (EMC) suggested that SVC was just a [bump in the wire] which could not possibly improve performance of existing disk arrays. IBM showed clients that putting cache(SVC) in front of other cache(back end devices) does indeed improve performance, in the same way that multi-core processors successfully use L1/L2/L3 cache. Now, EMC is claiming their cache-based VPLEX improves performance of back-end disk. My how EMC's story has changed!
So now, EMC announces VPLEX, which sports a blend of SVC-like and Invista-like characteristics. Based on blogs, tweets and publicly available materials I found on EMC's website, I have been able to determine the following comparison table. (Of course, VPLEX is not yet generally available, so what is eventually delivered may differ.)
Scalable, 1 to 4 node-pairs
One size fits all, single pair of CPCs
SVC-like, 1 to 4 director-pairs
Works with any SAN switches or directors
Required special "smart" switches (vendor lock-in)
SVC-like, works with any SAN switches or directors
Broad selection of IBM Subsystem Device Driver (SDD) offered at no additional charge, as well as OS-native drivers Windows MPIO, AIX MPIO, Solaris MPxIO, HP-UX PV-Links, VMware MPP, Linux DM-MP, and comercial third-party driver Symantec DMP.
Limited selection, with focus on priced PowerPath driver
Invista-like, PowerPath and Windows MPIO
Read cache, and choice of fast-write or write-through cache, offering the ability to improve performance.
No cache, Split-Path architecture cracked open Fibre Channel packets in flight, delayed every IO by 20 nanoseconds, and redirected modified packets to the appropriate physical device.
SVC-like, Read and write-through cache, offering the ability to improve performance.
Space-Efficient Point-in-Time copies
SVC FlashCopy supports up to 256 space-efficient targets, copies of copies, read-only or writeable, and incremental persistent pairs.
Like Invista, No
Remote distance mirror
Choice of SVC Metro Mirror (synchronous up to 300km) and Global Mirror (asynchronous), or use the functionality of the back-end storage arrays
No native support, use functionality of back-end storage arrays, or purchase separate product called EMC RecoverPoint to cover this lack of functionality
Limited synchronous remote-distance mirror within VPLEX (up to 100km only), no native asynchronous support, use functionality of back-end storage arrays
Provides thin provisioning to devices that don't offer this natively
Like Invista, No
SVC Split-Cluster allows concurrent read/write access of data to be accessed from hosts at two different locations several miles apart
I don't think so
PLEX-Metro, similar in concept but implemented differently
Non-disruptive tech refresh
Can upgrade or replace storage arrays, SAN switches, and even the SVC nodes software AND hardware themselves, non-disruptively
Tech refresh for storage arrays, but not for Invista CPCs
Tech refresh of back end devices, and upgrade of VPLEX software, non-disruptively. Not clear if VPLEX engines themselves can be upgraded non-disruptively like the SVC.
Heterogeneous Storage Support
Broad support of over 140 different storage models from all major vendors, including all CLARiiON, Symmetrix and VMAX from EMC, and storage from many smaller startups you may not have heard of
Invista-like. VPLEX claims to support a variety of arrays from a variety of vendors, but as far as I can find, only DS8000 supported from the list of IBM devices. Fellow blogger Barry Burke (EMC) suggests [putting SVC between VPLEX and third party storage devices] to get the heterogeneous coverage most companies demand.
Back-end storage requirement
Must define quorum disks on any IBM or non-IBM back end storage array. SVC can run entirely on non-IBM storage arrays
HP SVSP-like, requires at least one EMC storage array to hold metadata
SVC 2145-CF8 model supports up to four solid-state drives (SSD) per node that can treated as managed disk to store end-user data
Invista-like. VPLEX has an internal 30GB SSD, but this is used only for operating system and logs, not for end-user data.
In-band virtualization solutions from IBM and HDS dominate the market. Being able to migrate data from old devices to new ones non-disruptively turned out to be only the [tip of the iceberg] of benefits from storage virtualization. In today's highly virtualized server environment, being able to non-disruptively migrate data comes in handy all the time. SVC is one of the best storage solutions for VMware, Hyper-V, XEN and PowerVM environments. EMC watched and learned in the shadows, taking notes of what people like about the SVC, and decided to follow IBM's time-tested leadership to provide a similar offering.
EMC re-invented the wheel, and it is round. On a scale from Invista (zero) to SVC (ten), I give EMC's new VPLEX a six.
Well, I'm back safely from my tour of Asia. I am glad to report that Tokyo, Beijing and Kuala Lumpur are pretty much how I remember them from the last time I was there in each city. I have since been fighting jet lag by watching the last thirteen episodes of LOST season 6 and the series finale.
Recently, I have started seeing a lot of buzz on the term "Storage Federation". The concept is not new, but rather based on the work in database federation, first introduced in 1985 by [A federated architecture for information management] by Heimbigner and McLeod. For those not familiar with database federation, you can take several independent autonomous databases, and treat them as one big federated system. For example, this would allow you to issue a single query and get results across all the databases in the federated system. The advantage is that it is often easier to federate several disparate heterogeneous databases than to merge them into a single database. [IBM Infosphere Federation Server] is a market leader in this space, with the capability to federate DB2, Oracle and SQL Server databases.
Storage expansion: You want to increase the storage capacity of an existing storage system that cannot accommodate the total amount of capacity desired. Storage Federation allows you to add additional storage capacity by adding a whole new system.
Storage migration: You want to migrate from an aging storage system to a new one. Storage Federation allows the joining of the two systems and the evacuation from storage resources on the first onto the second and then the first system is removed.
Safe system upgrades: System upgrades can be problematic for a number of reasons. Storage Federation allows a system to be removed from the federation and be re-inserted again after the successful completion of the upgrade.
Load balancing: Similar to storage expansion, but on the performance axis, you might want to add additional storage systems to a Storage Federation in order to spread the workload across multiple systems.
Storage tiering: In a similar light, storage systems in a Storage Federation could have different capacity/performance ratios that you could use for tiering data. This is similar to the idea of dynamically re-striping data across the disk drives within a single storage system, such as with 3PAR's Dynamic Optimization software, but extends the concept to cross storage system boundaries.
To some extent, IBM SAN Volume Controller (SVC), XIV, Scale-Out NAS (SONAS), and Information Archive (IA) offer most, if not all, of these capabilities. EMC claims its VPLEX will be able to offer storage federation, but only with other VPLEX clusters, which brings up a good question. What about heterogenous storage federation? Before anyone accuses me of throwing stones at glass houses, let's take a look at each IBM solution:
IBM SAN Volume Controller
The IBM SAN Volume Controller has been doing storage federation since 2003. Not only can IBM SAN Volume Controller bring together storage from a variety of heterogenous storage, the SVC cluster itself can be a mix of different hardware models. You can have a 2145-8A4 node pair, 2145-8G4 node pair, and the new 2145-CF8 node pair, all combined together into a single SVC cluster. Upgrading SVC hardware nodes in an SVC cluster is always non-disruptive.
IBM XIV storage system
The IBM XIV has two kinds of independent modules. Data modules have processor, cache and 12 disks. Interface modules are data modules with additional processor, FC and Ethernet (iSCSI) adapters. Because these two modules play different roles in an XIV "colony", that number of each type is predetermined. Entry-level six-module systems have 2 interface and 4 data modules. Full 15-module systems have 6 interface and 9 data modules. Individual modules can be added or removed non-disruptively in an XIV.
IBM Scale-Out NAS
The SONAS is comprised of three kinds of nodes that work together in concert. A management node, one or more interface nodes, and two or more storage nodes. The storage nodes are paired to manage up to 240 nodes in a storage pod. Individual interface or data nodes can be added or removed non-disruptively in the SONAS. The underlying technology, the General Parallel File System, has been doing storage federation since 1996 for some of the largest top 500 supercomputers in the world.
IBM Information Archive (IA)
For the IA, there are 1, 2 or 3 nodes, which manages a set of collections. A collection can either be file-based using industry-standard NAS protocols, or object-based using the popular System Storage™ Archive Manager (SSAM) interface. Normally, you have as many collections as you have nodes, but nodes are powerful enough to manage two collections to provide N-1 availability. This allows a node to be removed, and a new node added into the IA "colony", in a non-disruptive manner.
Even in an ant colony, there are only a few types of ants, with typically one queen, several males, and lots of workers. But all the ants are red. You don't see colonies that mix between different species of ants. For databases, federation was a way to avoid the much harder task of merging databases from different platforms. For storage, I am surprised people have latched on to the term "federation", given our mixed results in the other "federations" we have formed, which I have conveniently (IMHO) ranked from least effective to most effective:
The Union of Soviet Socialist Republics (USSR)
My father used to say, "If the Soviet Union were in charge of the Sahara desert, they would run out of sand in 50 years." The [Soviet Union] actually lasted 68 years, from 1922 to 1991.
The United Nations (UN)
After the previous League of Nations failed, the UN was formed in 1945 to facilitate cooperation in international law, international security, economic development, social progress, human rights, and the achieving of world peace by stopping wars between countries, and to provide a platform for dialogue.
The European Union (EU)
With the collapse of the Greek economy, and the [rapid growth of debt] in the UK, Spain and France, there are concerns that the EU might not last past 2020.
The United States of America (USA)
My own country is a federation of states, each with its own government. California's financial crisis was compared to the one in Greece. My own state of Arizona is under boycott from other states because of its recent [immigration law]. However, I think the US has managed better than the EU because it has evolved over the past 200 years.
The Organization of the Petroleum Exporting Countries [OPEC]
Technically, OPEC is not a federation of cooperating countries, but rather a cartel of competing countries that have agreed on total industry output of oil to increase individual members' profits. Note that it was a non-OPEC company, BP, that could not "control their output" in what has now become the worst oil spill in US history. OPEC was formed in 1960, and is expected to collapse sometime around 2030 when the world's oil reserves run out. Matt Savinar has a nice article on [Life After the Oil Crash].
United Federation of Planets
The [Federation] fictitiously described in the Star Trek series appears to work well, an optimistic view of what federations could become if you let them evolve long enough.
Given the mixed results with "federation", I think I will avoid using the term for storage, and stick to the original term "scale-out architecture".