Home | GestaltIT | Enterprise Computing: Do We Need FAST v1, EMC?

Enterprise Computing: Do We Need FAST v1, EMC?

0 Flares Twitter 0 Facebook 0 Google+ 0 StumbleUpon 0 Buffer 0 LinkedIn 0 Filament.io 0 Flares ×

So, here’s my rash statement from Twitter last night: “If FAST isn’t free, I don’t want it!  All it’s doing is automating process I could script/do manually”.  It’s a bold statement, I know, so is FAST really offering something better than what could be achieved today using EMC’s Symmetrix Optimizer?

Hot Spots

EMC’s Symmetrix architecture (18 years old and counting, I believe) uses the concept of disk hypers to present LUNs.  Each physical disk is carved into a number of slices, which are then recombined to create LUNs to present to a host.  A mirrored (RAID-1) LUN uses two hypers, a RAID-5 (3+1) LUN uses 4.  EMC ensure general performance by setting standards on how LUNs are created from hypers and that’s reflected in a “binfile” layout.  However despite this sensible planning, it is possible (especially as hard drives are now much larger and contain many more hypers) that two hypers on a single physical disk could be highly active and so contend against each other – in other words “hot spots” on disk.

Optimizer helps alleviate the issue of hot spots by exchanging the high I/O hypers with low I/O ones, distributing busy LUNs across more physical spindles.  This is classic load balancing where resources are distributed across the available infrastructure in order to obtain better overall generic performance.  EMC have now rebranded Optimizer as part of Ionix for Storage Resource Managment, but it’s still effectively the same product.  Hyper swaps can be managed automatically, based on historical performance data.  They can also be user-defined – a manual swap at the users request.

Although tedious (and not as well automated as Hitachi’s HiCommand Tiered Storage Manager), in theory Optimizer could be used to manually move workload between storage tiers.  In fact, Optimizer is already aware of a tiered storage infrastructure.  Here’s a quote directly from the ControlCenter 6.1 manual:

“Optimizer is also aware of physical drives that operate at different speeds, as well as location of the data on the physical media, which influences the I/O rate. This information is used when determining which logical devices to move.”

So with a little bit of knowledge on the layout of data on a Symmetrix array, it would be possible today to use Optimizer to perform LUN-based FAST.

Load-Balancing Versus Policy

Unfortunately, simple load-balancing of I/O across a storage array doesn’t offer what should be seen as the next generation of storage tiering.  Where Storage Tiering 1.0 was about offering multiple layers of storage within the same physical infrastructure and manually placing or moving LUNs to the appropriate tier, Storage Tiering 2.0 will be about establishing policies that determine more service-based measurements of the performance and availability customers receive. 

A policy-based approach would allow rules to be established on how data at the application layer moves between tiers.  This is a critical distinction from the load-balancing  methodology earlier described.  As an example, where an application was known to require higher performance at a certain time of day or day of the week, data could be moved proactively to a faster tier of storage, returning later once the high I/O workload had completed.  Whilst achievable using Optimizer, there’s no doubt the process of application migration would be tedious and time consuming.  I expect the v1.0 implementation of FAST will simply package up Optimizer into a tool that automates the migration of related data between tiers.  Don’t forget, other vendors have been offering this feature for some time – for example Hitachi and Tiered Storage Manager.

Increasing Granularity

Now LUN-based migration has its benefits.  Where large numbers of disks exist in an infrastructure, application data can be placed or moved to the most appropriate location as required.  However with the introduction of solid state disks (SSDs), a more granular approach is needed as the number of SSDs deployed in an array is likely to be low due to their excessive cost.  Moving an entire application (or even LUN) to SSD will be undesirable unless that application can take full use of the SSD hardware.  There are very few, if any, applications that require high-intensity read/write activity from every piece of application data all the time.

Block-level tiering offers a higher level of granularity to the placement of data.  A LUN can be split into blocks and placed across multiple layers of storage technology including traditional HDDs and faster SSDs.  Selective placement will ensure the more efficient use of expensive SSD media by placing only the highly active data onto it.

All of a sudden with increased granularity we’re back to Storage Tiering 1.0 where data is being placed on faster technology purely based on increasing overall system performance.  This is a feature Compellent have been offering for some time.  Data is migrated up or down the tier hierarchy on a daily basis, subject to performance figures over a 12-day period.  This level of granular performance management is possible because data is stored in a block-based structure.  Unfortunately for EMC, the hyper design legacy represents a technical challenge in making FAST version 2 a reality. 

Patent Rights

As just mentioned, Compellent already offer block-based data migration in their products.  At a recent dinner in London with the Compellent team, they highlighted their strong position in the market, protected by patents covering block-level data migration between tiers.  You can find the filed patent here.  Compellent use the term “Data Progression” to describe how blocks are moved between tiers based on I/O activity.  As I/O activity is monitored over time, it is possible to determine the most appropriate tier of storage to use when expanding capacity.  Typically these are lower tier SATA drives, as initial performance requirements are usually over-estimated.  This metholodogy is very much Storage Tiering 1.0 discussed earlier.

Compellent aren’t the only people claiming rights to block-level tiering within a storage array.  I’ve also found the following patent application from IBM, filed by Barry Whyte, Steve Legg and others.  If IBM and Compellent both claim to have invented the FAST concept, how does that position EMC?  Do they have an earlier patent which trumps these two?

Summary

Storage Tiering 1.0 provides performance management of storage arrays.  Storage Tiering 2.0 extends this to offer policy-driven optimisation offerings.  Both of these technologies are available today from existing vendors in one format or another.  EMC will simply be playing catchup with these vendors once FAST 1 & FAST 2 are released.  I’d like to be surprised and see EMC offer something the competition currently don’t.  I’m not holding my breath…

About Chris M Evans

Chris M Evans has worked in the technology industry since 1987, starting as a systems programmer on the IBM mainframe platform, while retaining an interest in storage. After working abroad, he co-founded an Internet-based music distribution company during the .com era, returning to consultancy in the new millennium. In 2009 Chris co-founded Langton Blue Ltd (www.langtonblue.com), a boutique consultancy firm focused on delivering business benefit through efficient technology deployments. Chris writes a popular blog at http://blog.architecting.it, attends many conferences and invitation-only events and can be found providing regular industry contributions through Twitter (@chrismevans) and other social media outlets.
  • http://storagebod.typepad.com Martin G

    Chris, I don’t think it matters a jot to EMC whether they have a patent which trumps IBM’s due to the cross-licensing agreement between the two of them. And if EMC can be first to market with an enterprise array which does automated storage tiering, good luck to them. But just as thin-provisioning is becoming just another feature, so will automated storage tiering.

  • Chris Evans

    Martin

    I guess only time will tell. However I would say that Automated Storage Tiering as a feature needs to be free. It’s not the sort of feature that directly translates into easily measurable cost savings (unlike generic tiering or even thin provisioning).

    Chris

  • http://storagebod.typepad.com Martin G

    Oh, it’s got to become part of the base feature set; it should be tied into the very core of the array and be completely invisible to the end-user. But ‘first-mover’ advantage is the ability to charge for it and probably charge a premium for it. And EMC have set themselves up to be shot down; if someone ships the equivalent of Fast V2 on an Enterprise array before EMC ship FAST v2; there’s going to be red faces…

  • http://www.ibm.com/developerworks/blogs/page/InsideSystemStorage Barry Whyte

    Chris,

    This is actually the one that covers automated tiering :

    http://www.patentstorm.us/applications/20080168228/fulltext.html

    Be interesting when Compellent first filed theirs 🙂

  • http://thestorageanarchist.com the storage anarchist

    While indeed FAST v1 essentially does what you can do manually, it automates the process – indeed, similarly to what Symm Optimzier does (although Symm Optimizer does not move across different types/speeds of drives). But FAST introduces the notion of Policies, allowing storage admins to define different porportions of Flash, FC and SATA for different applications.

    And this Automation is indeed the value proposition; many customers today complain that they don’t have the people or time required to determine the appropriate tiering for either their current or their new applications; this leaves many using the de-facto 15K rpm drive as their platform, when either Flash or SATA (or a mix) might be more cost-effective for both CAPEX and OPEX.

    I’ll defer the pricing discussion until after GA announcements later this quarter. And the patent topic really isn’t something I can comment upon at this time.

  • http://www.compellentblog.com Liem Nguyen

    Hi Chris,

    Thanks very much for giving automated tiered storage the attention it deserves. This type of technology should be made available to all enterprises, whether they’re small and only require a few terabytes or whether they’re global companies. Of course I think Compellent has the best tiered storage solution :-), but the important thing is that end-users carefully consider what’s available today that they can grow into even if they’re not ready to pay for it today. We felt that way when we launched automated tiered storage in 2005 and we still believe it. That’s why we’re still evolving the technology, working on Storage Tiering 3.0 so to speak, because we know the EMCs and IBMs of the world will keep working to catch up one day.

    In several important ways, Compellent’s Data Progression technology is both Storage Tiering 1.0 and 2.0 by your definition. Let me share a few thoughts:

    We think relative frequency of access is actually a better indicator of end user need instead of performance. The way Compellent’s Dynamic Block Architecture works is almost like tracking and managing the popularity of blocks. We assume the data blocks people need the most should be on their highest performing tier of storage, whether SSD or FC. The ones they don’t need the most should be on less expensive storage like SATA. So it’s really tiering by frequency of access to increase both performance and cost savings.

    Also, we already provide policy-based tiering – we just call the policies “profiles.” The default tiered storage profile is based on best practices feedback provided by thousands of sites using Data Progression. Most of our customers prefer the purely set-it-and-forget-it tiering method provided by the default profile. If users want more granular control they can change the profiles at any point in time through our GUI, and they can apply the same profile to multiple volumes. For instance, they can create a profile stipulating the percentage of a volume that will always be written to tier 1, tier 2 and tier 3. And if their business needs require, they can set a profile to dedicate 100% of a given volume to a single tier, such as SSD.

    BTW, we filed the first patent back on March 22, 2007 :-). Here’s the link:

    http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4&f=G&l=50&co1=AND&d=PTXT&s1=aszmann&s2=aszmann&OS=aszmann+AND+aszmann&RS=aszmann+AND+aszmann

    Thanks for taking the time to carefully analyze the available tiered solutions today and for giving me the opportunity to share my viewpoint. If you or anyone else has questions or would like more information, you can find me at twitter.com/liemnguyen or lnguyen@compellent.com.

    Liem

  • Pingback: Twitter Trackbacks for Enterprise Computing: Do We Need FAST v1, EMC? « The Storage Architect [thestoragearchitect.com] on Topsy.com()

  • Pingback: uberVU - social comments()

  • Pingback: Policy! Policy!! Policy!!! | StorageNerve()

  • Pingback: Policy! Policy!! Policy!!! – Gestalt IT()

  • Pingback: FAST, miles and miles away!!! | StorageNerve()

  • Pingback: My mother-in-law and data storage. « What's this got to do with…()

  • http://na Bob Roberts

    We are intentionally skipping FAST V1. At this point, I do not have a warm fuzzy about the migration path from FAST V1 to FAST V2. Thick to thin, etc…

  • Paul Knowlig

    Actually – FAST is free. Into FAST bundled several products by cost of one. Check…

0 Flares Twitter 0 Facebook 0 Google+ 0 StumbleUpon 0 Buffer 0 LinkedIn 0 Filament.io 0 Flares ×