VSAN emerges at a WHOPPING 32 nodes and two MEEELION IOPS

But VMware's not after top tier storage workloads … yet

VMware has revealed the details of its virtual storage area network, the prosically-named VSAN.

Virtzilla revealed the existence of VSAN at last year's VMworld and quickly offered a beta. That's been taken up by 12,000 folks, VMware says. They've given it a jolly good shakedown cruise and next week it will emerge as a product called VSAN 5.5.

If you think it's odd to launch a product's first iteration as a point product, the numbering is designed to match vSphere 5.5, VMware's current software flagship. Doing so also signals that VSAN isn't just a new product or a virtual appliance: it's a part of the vSphere kernel and will appear in vSphere Update 1, which is due within days. The update will allow VSAN to be switched on with a click or two and provision of a licence key.

If you buy that licence you'll get a virtual storage array capable of scaling to 32 nodes, 4.5 petabytes and two million IOPS, or operating on just three nodes. VMware's Aaron Steppat said the company is “pretty stoked” (Australian for very pleasantly surprised and excited) about the upper levels of capacity and performance.

To reach those figures you'll need servers that pack at least one SSD and one boring old spinning rust disk. Who might provide such servers, or disks? If you think back to its Partner Exchange event last month, VMware said VSAN has "broad partner ecosystem support" and the likes of Cisco, Dell, EMC, Fusion-io, HP, HGST, IBM, Intel, LSI, Samsung Electronics, SanDisk and Seagate" will offer hardware on which it can run.

Steppat told The Reg major server vendors will shortly come to the party with products offering that specification and approved by Virtzilla as ready for service inside VSANs.

Jessup added that VMware is going after three markets with VSAN, with virtual desktops (VDI) the main target. VSAN will be suggested as a way to address boot storms, the storage-crushing moments early in the work day when many workers log on to virtual desktops at once. Flash array vendors say they've got that problem licked, which Jessup acknowledged. VMware's alternative is to assemble a virtual array to handle boot storms, rather than invest in an all-flash array to do the job.

Them's fighting words for several VMware partners, and Steppat said Virtzilla knows it but is prepared to take some heat.

“As we broaden our footprint and do to networking and storage what we did to the processor, we know there are toes we will step on,” he said. CPU vendors came to understand VMware is not a predator, he added, and he expects storage vendors will too.

The second scenario VMware is aiming for is test and development, tasks Steppat said can often be usefully offloaded from primary storage. Instead of letting developers bomb production SANs, he suggested, elastic virtual arrays should be enough for them to play with.

Target market three is disaster recovery. Many organisations acquire replica arrays for their disaster recovery sites, Steppat said, but resent the expense. Instead readying a virtual array as a failover target will, he feels, excite some customers.

Three fine scenarios, but none making VSAN a threat to a conventional array. Which looks rather kind to traditional array vendors. One of which, by complete co-incidence, owns the majority of VMware.

Steppat disavowed your correspondent of the notion VMware is going soft on its parent, EMC.

“We have tested a whole range of use cases and found the three that have the biggest value,” he said. “As time goes on we may say we can get the business critical apps in there too, but those apps have other complications.”

Complications that we imagine EMC knows how to fix.

Does VSAN matter?

Virtual SANs are nothing new. VMware itself released its VSA storage appliance back in 2011. As we've noted previously, HP has had one for years, EMC and NetApp sell 'em, Nexenta is a player and Maxta is spoken of highly. Nutanix loves the idea.

So why does VSAN matter?

Gartner research director Michael Warrilow, who covers virtualisation, says virtual SANs are inevitable.

"If VMware don't do it, someone else will. And don't forget EMC has ViPR: even they know this is necessary.

"There is always going to be a place for the hardware array," Warrilow he told The Reg. "But it has been the place for everything."

The advent of solid state disks means virtual SANs can deliver performance worthy of some workloads, and Warrilow feels that means "there are lower-risk workloads where you can shave a lot of cost by going a VSAN."

He therefore expects VSAN will "find a nice little place in the middle to lower end of the enterprise storage market."

VMware thinks it can go beyond that one day. Who'd bet against it? ®

Update

The Reg was pre-briefed on VSAN before the all-singing, all-dancing launch, at which a few more details were revealed, namely:

• There's a 100 virtual machine per-node limit;
• Vmware employee Cormac Hogan has blogged an explanation for the IOPS figure of two million, writing it was reached "using IOmeter 100% read, 4KB block size. Also 640K IOPS using IOmeter with 70/30 read/write ratio
• Nodes can host up to 32 disks apiece
• Cisco, Dell, Fujitsu, IBM and Supermicro will release VSAN nodes in the next 30 days
• Nodes will need a 1Gbps NIC, but a 10Gbps NIC will be better
• VMware has fired up VSAN labs

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