Real storage in a virtual world

Storage is front and center at VMworld this week. And well it should: storage has always been the virtual machine's (VM) Achilles heel. Can it be fixed?
Written by Robin Harris, Contributor on

VMware's brand of server virtualization is the industry leader. VMworld 2011 has attracted a reported 20,000 people to a broiling Las Vegas.

But strolling the vendor expo it looks like a storage show. EMC and Isilon have booths up front, as do Coraid, Fusion-io and NetApp.

Emerging vendors like Tintri, Avere, Nexenta, Whiptail, Nimble Storage, Sanbolic, Nimbus, Virsto, Scale Computing, Pure Storage, StorSimple and Nutanix are also showing. And that's hardly a complete list.

Obviously, VMware has a storage problem opportunity.

Storage is the hard part VMware's biggest selling point is VMotion: the ability to take a running app and migrate it to another physical server without shutting it down. Great for system maintenance and usage spikes.

But VMware's weak spot has been moving the app's data: an app isn't good for much without its data.

Other issues include:

  • VM storage. Virtual machines are large files - averaging 20-60GB each - and storing thousands of them chews up a lot of expensive enterprise capacity.
  • VDI. Virtual Desktop Infrastructure is hot: give every employee or student a VM and they can grab any PC, boot their VM and have all their apps and data. But VDI boot storms kill most storage systems and keep users waiting far too long.
  • The I/O blender. Storage systems have long relied on the observation that data is accessed in clumps. But when you have 25 VMs each accessing their own data, the clumps become a smear and traditional storage optimizations don't work. Now what?
  • Backup and deduplication. Over 90% of the bits in a VM are the same, so why store them over and over? And they have to be backed up.

The Storage Bits take Virtualization schemes like VMware and Microsoft's Hyper-V can't reach their full potential without storage that is as flexible and performant as the VMs. But while one VM looks much the same as another, the user and application data are always unique.

VMware's storage problem recapitulates computing's earliest days: the CPUs were easy; it was the storage that held them back.

And so today's 10Gig ports, flash and fast disk, dozens of gigabytes of DRAM, smart software and much ingenuity are working to solve the problems of a key enabling technology for the future of computing: real storage optimized for a virtual world.

Comments welcome, of course. I'll be on the show floor today looking for the coolest stuff. Stay tuned.

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