What's that racket? Oh my God, it's VMware's vSAN bull in the disk array shop
New robo-storage software versus the rivals
VMware has launched its virtual storage area network (vSAN) technology; pretty much unleashing a raging bull into a
china virtual storage appliance shop and watching all the crockery racks of electronics go flying.
Available now as a beta, vSAN can create a virtualised storage array that pools the disks and flash drives of a cluster of servers running VMware's ESXi tech. How are the various rival virtual storage appliance (VSA) suppliers affected? In alphabetical order we have:
Datacore has its own Virtual SAN Appliance software, but this is enterprise class and has a vast array of SAN and related functionality built on top of it. VMware's vSAN is no contest in the markets that Datacore's SANsymphony is sold into.
Dell had an EqualLogic VSA planned, known as Project Mercury. It was canned and it's not known if Dell has a VSA strategy. Any intention to provide VSA functionality for VMware ESXi hosts likely just got nuked.
EMC (which owns VMware) has several products that are affected by VMware's vSAN. It has an Atmos VSA that customers use for testing out Atmos functionality prior to deciding to install it big time. It's not a full product itself, so to speak.
EMC's ViPR is a product that separates storage control and data planes, and functions under several hypervisors - whereas, by definition, vSAN is ESXi-only. ViPR is also enterprise class and (right now) vSAN is not. Read Chad Sakac's blog for an in-depth discussion of ViPR and vSAN.
A third overlap area is EMC's ScaleIO technology, used to build a flash-based SAN from hundreds if not thousands of servers' non-volatile NAND stores. This is way beyond the capabilities of VMware's vSAN, which is limited in server numbers and uses flash as a caching tier above disk storage. We understand also that ScaleIO is for applications that don't necessarily run in virtualised servers. ScaleIO has also been characterised as a more reliable Amazon Elastic Block Store for an entire data centre. It's clear that EMC will add storage services to vSAN, such as Avamar and RecoverPoint and possibly others, as well as providing server flash cache hardware.
Where's my get-out-of-VMware-jail card?
HP has its StoreVirtual VSA product, the old LeftHand VSA, which provides an iSCSI SAN access protocol for apps running in the servers. VMware's vSAN is just for ESXi servers, so StoreVirtual VSA will find its appeal to VMware server operators substantially reduced, depending on vSAN pricing. But StoreVirtual VSA supports Microsoft's Hyper-V and that's its get-out-of-VMware-jail card.
HP also has a StoreOnce VSA, a deduplicating disk backup system. VMware's vSAN has no deduplication capability or backup data service. EMC will probably add an Avamar backup data service to vSAN thus giving StoreOnce VSA a problem. Cue lots of "my backup VSA is better than your backup VSA" type conversations.
NetApp has its ONTAP Edge VSA product, providing FAS Array ONTAP functionality on a group of ESXi servers' directly attached storage. Oh dear; it looks as though VMware has stuffed NetApp, VSA-wise. But NetApp can point to its ONTAP functionality and say vSAN 1.0 is, well, a first-generation product so don't buy it.
Your humble sage on El Reg's storage desk thinks ONTAP Edge will quickly gain Hyper-V support, and maybe KVM and Xen also, and may, like any other VMware-hosted non-VMware VSA, over time fade away on ESXi servers.
PernixData's FVP product is not a VSA but it does virtualise ESXi servers' flash into a pool of VM-accelerating cache for ESXi itself. So it accelerates virtual machines and, if those VMs are VSAs, then it accelerates the VSAs, including, logically, VMware's own vSAN. What PernixData is doing is catching a ride on a tiger and then whipping the beast to go faster. Scary stuff - as long as PernixData knows what it's doing, everything should be all right. But, methinks, VMware should buy it.
Sanbolic has its Melio 5 software with VSA features. This is a broad-ranging product that is enterprise class, and against which VMware's vSAN is a version-one product lacking many enterprise features. Sanbolic has substantial feature superiority and, for now, an enterprise focus that vSAN lacks.
StorMagic supplies its SvSAN VSA which runs on VMware servers. Oops. Not such a good idea now. It provides high-availability between two servers and is targeted at remote and branch offices. Feature-wise it is way better than VMware's original VSA (you can find a comparison here).
VMware's vSAN also has high-availability (HA) features so StorMagic's initial reaction will be to point to its better HA features while it works out how to avoid getting steamrollered by VMware's VSAN juggernaut. Looking at other hypervisors would seem a smart idea.
There are probably VSAs from other suppliers that we've missed in this overview; apologies for that.
Reading Chuck Hollis' blog post will give you a broad picture of VMware's vSAN and how it does what it does.
Finally, a question; what would be the effect of Microsoft adding a VSA to Hyper-V? Ditto RedHat and Citrix to their hypervisors? Long-term, VSAs from any other suppliers could die out, don't you think? ®
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