Home | Uncategorized | Enterprise Computing: DMX-4 Is Dead – Long Live DMX-5!

Enterprise Computing: DMX-4 Is Dead – Long Live DMX-5!

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

DMX-4 to DMX-5 Conversion


Chris Mellor posted a great article recently, speculating on the future of certain storage products.  He hinted at a new high end array from EMC, presumably an extension to the DMX range – tentatively titled DMX-5.  

We’re about due for a new hardware release.  Looking back, the schedule has been:

  • DMX-4 – 16th July 2007
  • DMX-3 – 25th July 2005
  • DMX-2 – 9th February 2004
  • DMX – 3rd February 2003
  • Symm 5.5 – 10th September 2001
  • Symm 5 – April 2000

So, expect a new array announcement around June/July this year.  I’ve heard rumours of customers with secret EMC arrays, however they could have turned out to be Atmos and therefore just a bit of hot air.  Alternatively, they may have been the new DMX-5 – although I’ve not got any proof to back that theory up.

Will EMC retain the DMX/Symmetrix heritage or will they take the opportunity to leapfrog the competition with something new?

 The current DMX range suffers from a number of issues.  The underlying architecture uses the concept of hypers to create LUNs, so RAID is based on creating LUNs from discrete slices of a disk.

Problem 1: As hypers are used to create LUNs, a LUN will consist of a maximum of eight hypers across 8 disks using RAID-5 (7+1).  Creating these LUNs means making a hyper of a size which is divisible by the intended LUN size, so if you want a LUN of 70GB on RAID-5 7+1, then you need to create eight 10GB hypers.  If you want to stripe across more devices, then you have to go with meta-devices, which concatenate more than one LUN together.  This means either bigger LUNs or carving smaller hypers.  Typically though, an array configuration will be pre-determined at installation time and making changes to hyper sizes can be a torturous process, which is usually avoided. 

Problem 2: Legacy Code.  Symmetrix and DMX all worked off the concept of physical mirrors of a logical LUN – commonly known as mirror positions.  A BCV and an SRDF device become a mirror position, with a maximum of four permitted.  Without me offending the excellent programmers who have crafted the Enginuity microcode, EMC have had to effectively shoehorn new features in – for example Snaps & Clones to replace BCVs and Thin Provisioning.  The inherent Symmetrix/DMX design doesn’t lend itself to the implementation of new features.

 So, will EMC make a break and go for a complete redesign for DMX-5?  Wide striping seems essential, as does dynamic LUN creation, however top of my wish list is the ability to move data between tiers of storage within the same array – and for this to be granular enough to make it useful.

This requirement leads on to full policy-based placement of data and automated migration between tiers to maintain the service level requirements of the policy.  In turn, this leads to integration with Atmos, providing a full end-to-end policy-based data placement and management.  Wouldn’t that be good!

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://blog.fosketts.net Stephen Foskett

    Yes, Chris, having a DMX that was as flexible and granular as the competition in terms of wide striping, mirroring, and replication would be a Very Good Thing. Moshe’s Symmetrix was brilliant, but its time has passed – even he has moved on. Let’s get rid of mirror positions and metas once and for all!

    But I’m betting that DMX-5 will be much more evolutionary than revolutionary…

  • Chris Evans

    Stephen, I guess so. Thing is, as we all know, HDDs are more and more reliable, so mid-range devices like 3Par are making hay while the sun shines. EMC know that because they claim 5-nines availability for Clariion.

    Why pay for DMX-level quality, when other technology out there does the job at half the price?

  • http://storagezilla.typepad.com Storagezilla

    Virtual Provisioning solves a lot of that today. Engineering ran session on it at EMC World 08 as to why DMX customers should be using it right now.

  • Techmute

    @zilla – It isn’t that Virtual Provisioning isn’t a great technology, it is more that the license is fairly expensive the last time I checked.

  • Pingback: Cinetica Blog » Un 2009 Di Aspettative!()

  • http://blogs.rupturedmonkey.com Nigel

    May be you should alter the pic to strike out the EMC and replace it with “Cisco” –


  • http://storagezilla.typepad.com Storagezilla

    Techmute: Virtual Provisioning is priced comparable to that of the Thin Provisioning offerings from DMX competitors.

  • Pingback: Tony Asaro’s Blog Bytes » Blog Archive » External Blog Posts You Should Read()

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