VMware & Virsto

Howard Marks has a great piece on VMware buying Virsto over at Network Computing (link is below):

Some of my fellow analysts have lumped Virsto into the flash acceleration category along with caching solutions like Proximal Data, Sandisk’s Flashsoft and Intel’s CAS. While Virsto can use flash to accelerate some storage I/O, it’s not primarily a flash acceleration product. In fact, Virsto is a log-based, clustered file system that uses a dedicated log device, which can be a shared SSD, to accelerate virtual machine I/O.

I saw Virsto for the first time at VMworld 2012, and it looked interesting as something that tries to turn a lot of the random I/O from a virtualization environment back into sequential I/O that arrays can better handle, while adding a ton of modern features missing from vSphere. I’ve been asked a couple of times now about what I think about the recent news, and much of it mirrors what Howard is thinking. I’d add a couple of things.

First, Howard is correct, VMware’s current disk technologies and filesystems are starting to show their age. VMFS has problems with snapshots and performance, a problem I’ve been dealing with in some of my environments. VMDK may not have actual problems itself, but it also doesn’t help solve problems with I/O alignment, space efficiency/UNMAP, etc. VMDK is getting replaced with Space Efficient Sparse Disks, a new technology rolled out with vSphere 5.1. SE Sparse disks have dynamic block sizes and the ability to reclaim space from a guest OS, essentially re-thin provisioning a VM automatically. While SE Sparse disks are only for VDI right now I wouldn’t be surprised to see it available for regular guests in the next major vSphere release. On the VMFS front VMware has talked about Virtual Volumes, or vVols, which mashes up the concept of the datastore with VASA array communications. Under vVols, Storage Profiles get a lot more powerful because now you can assign performance and availability requirements to a VM, and then the whole virtualization stack from the storage on up can work to manage those expectations. The problem with vVols is that it relies on hardware vendors, which goes against the software-defined data center philosophy that VMware has. It’s also yet-another-kludge on top of other kludges that work around the fact that the way we are forced to use storage hasn’t fundamentally changed since SCSI appeared in 1981.

The second piece of this in my mind is VMware’s Distributed Storage, or vSAN as it’s been called. VMware talked about their vSAN distributed storage work at VMworld 2012, and it’s a technology that would basically turn local storage into replicated, usable space for hosting VMs. It would turn VMware into a competitor in the Nutanix/Simplivity/Scale space, except with hardware agnosticism. You take your run-of-the-mill Dell PowerEdge R720, cram some SSD and SAS in it, add it to the cluster, and the cluster manages the rest. Just like building blocks for the data center. For VMware is that this is brand new technology they are building from the ground up. That’s a problem, since it takes a lot of time & effort to come up with those new technologies, and even more time to make them reliable. Nutanix just shipped its third major release of their products (NOS 3.0) and definitely has first-mover advantage in the converged, building-block space. VMware doesn’t even have a 1.0 product, and with VMware’s reputation for QA and the fact that a second major release would be two to three years away VMware is basically out of this game.

So you see why they bought Virsto. First, Virsto has a working, shipping, proven code base right now, just needs integrating. Second, the product fits directly into the software-defined data center vision, bringing the logic back up out of the arrays and into the virtualization layer. Third, it brings to the table a load of modern storage features, like log-structured filesystem techniques, replication, use of SSD and flash for acceleration, storage tiering, thin provisioning, better snapshots, etc. These are all things VMware doesn’t have to invent anymore for VMFS, VMDK, vVols, and vSAN, they just have to integrate Virsto and roll the product out the door.



7 thoughts on “VMware & Virsto”

  1. Thanks for the shout out Bob. As I’ve been talking to people over the past few days about this it’s become clear to me we in the storage business need to start thinking smaller. When an enterprise SAN had 50-100 volumes and a file system was one type of data a volume or file system level snapshot made sense. In the virtual world the VM has to be the unit we work in.

    Virsto, tintri and Simplivity get this. Hopefully the rest of the industry will follow

    • Your comment about VMware pursuing software-defined storage despite being mostly owned by EMC made me think about the whole Apple philosophy that if you don’t cannibalize your own market someone will do it for you.

      I don’t think the rest of the industry will “get it” very quickly, but I also think it won’t matter because the old-style monolithic array vendors will have plenty of business for years. Storage admins, and enterprises in general, are extremely conservative when it comes to their storage. I know from personal experience that changing storage paradigms like this scares the crap out of most IT management, and as a result the technologies that we’re talking about right now won’t even be a consideration for most places for 5+ years. Especially given the FUD that EMC, IBM, and HDS spew.

  2. “With VMware’s reputation for QA … VMware is basically out of the game.” — LOL too true too true.

    But you forgot about VMware’s even more dismal record at integrating acquisitions.

    • I see that as part of their waffling about what sort of company they are. Their acquisition of Integrien has been good. Zimbra/SpringSource not bad, either, though those are largely their own standalone products. Wanova and Nicira are clear winners, too, waiting to be integrated more fully.

      The odd ones are SocialCast, SlideRocket, etc. No idea why they bought them, they’re niche services, and they certainly aren’t flourishing. Likewise with Digital Fuel & Cetas — after the way VMware botched EMC Infra/VMware Service Manager I have my doubts.

  3. I really enjoyed this article. I myself have been following the VMware acquisitions closely over the last year. I have written several articles trying to dissect each one.




    At the end of the day, there is no right or wrong answer, however it does demonstrate an urgent need to move into other areas besides selling licenses. My biggest concern with VMware even after acquiring these fantastic technology companies is VMware sales. Can they switch from selling licenses (the easiest thing in the world since VMware pretty much sells itself) to defining solutions to customers who have been buying solutions from other vendors for the longest time.

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