One of the new features of vSphere 5.0 is a VMware VSA, or virtual storage appliance. VSAs are nothing new, as HP and FalconStor have offered VSAs for vSphere for a number of years. VSAs work by using DAS (direct attached storage, e.g. SAS or SATA) and turn it into shared storage that enables HA features like storage vMotion, HA, FT and vMotion. Of course the primary reason to do this is cost. If you are a SMB or have a remote office, you can deploy a VSA for less money than a physical iSCSI SAN.
Basically you can install the VSA on two to three servers (one server configuration is NOT supported), and it will pool their storage using local RAID, and do network RAID across the physical servers. VMware claims 99.9% availability using vSphere HA. It also has tight integration with vCenter, so you can manage it in a single pane of glass, which is pretty cool.
The VSA is separately licensed, and not included in any vSphere edition. Each instance supports up to three nodes. However, vCenter will only support one VSA instance. So if you have a lot of remote offices and want to use VMware VSAs at them, you really won’t be able to do that. You would need to look at alternatives like HP. List price of the VMware VSA is 5,995 per server. You can also buy it with the vSphere 5 Essentials Plus SKU for a total of $7,995 for a limited time.
It is interesting to see VMware now directly competing with partners such as HP for storage business. The P4000 VSA is very feature rich, just like the physical P4xxx servers and include VAAI support. The VMware VSA v1.0 only supports NFS, so you don’t get any VAAI 1.0 features that you do with the P4000 VSA since it’s iSCSI based. You do get NFS storage I/O control, which is new to vSphere 5.0. The VMware VSA also will have a separate HCL, and pretty short at GA, but VMware says the list will rapidly expand as partners validate the solution.
During the Q&A of the live session it was a bit unclear how VMware calculates usable capacity of the VSA. So stay tuned for more details, once I find more information on the subject. Basically there’s a combination of RAID 10 and RAID 5 going on to provide solid data protection in the case of disk or node failure.
As a side note, some SKUs of the HP P4500 physical arrays come bundled with 10 VSA licenses that support up to 10TB each. And there’s no vCenter limitation of the number of P4000 VSAs you can use, so that becomes an excellent branch office solution which can scale up very nicely.
You can buy a P4500 model BQ888A which includes the 10 VSA licenses for $43K, so in essence you pay $4.3K for each VSA and get a free 14TB hardware SAS iSCSI array. The VMware pricing reinforces that the VSA is really for Essentials Plus customers, which probably wouldn’t pay $43K for a hardware iSCSI array.