One of the biggest IT costs for a small and midsize business is shared storage, like a NAS or a SAN. Even the most entry-level of SAN’s can cost $10K and up to purchase, plus usually another couple thousand dollars to get it deployed and learn how to use it. For a lot of small businesses, that’s their entire yearly IT budget.
The problem is that shared storage is absolutely needed to get the most out of a modern virtualized environment. Key vSphere features like vMotion, High Availability (HA), and Fault Tolerance (FT) all require some sort of shared storage. So what do you do if you don’t have that $10K or more to buy a shared storage device? You get a VMware vSphere Storage Appliance (VSA) instead! The VSA is software that turns your vSphere Hosts’ (servers) internal hard drives into a highly available (99.9%) redundant shared storage device.
With just 5 clicks, your internal hard drives are setup in a RAID array, mirrored across two or three hosts, and are immediately available within vCenter as a shared storage device for you to use to enable all of the advanced functionality within vSphere.
A VSA VM runs on each host in the cluster (up to 3 hosts), acting as the pass-through device to the hard drives on each host. It then sets up a type of NFS mirroring across each host to make sure your data is online and available, even in the event of a host crashing or needing maintenance.
In fact, I just did a quick quote on a major manufacturers website to see the price difference between 3 servers on the VMware VSA HCL and an entry-level 1GB iSCSI storage array from the same vendor.
The servers were configured as follows:
Dual Intel Xeon E5620
64GB RAM
6x1TB SATA HDD’s
The SAN was configured as follows:
Dual Storage Controllers
18x1TB SATA HDD’s
The servers, with a total of 18TB of raw storage plus enough horsepower to run a fairly large SMB’s entire virtualization setup cost $17,037 (without software), while the SAN alone was $19,476. The difference here being that once you add the VMware vSphere + VSA software to the servers, you’re ready to go. With the SAN, you still need to purchase servers to run the VMware vSphere software. Quite a savings, right?
Now, the VSA is not a replacement for all SAN/NAS devices, as it does not have a lot of the features those $10K storage devices do, like replication, snapshots, or clones. It also is limited to the expandability of your hosts for hard drive space and speed. Most modern shared storage devices can go to 100 disks or more – that’s not likely to fit within 3 servers. Nonetheless, if you need access to an inexpensive, redundant, set of storage for your smaller VMware environment, the VSA can definitely be the way to go.
What solution do you have in place for shared storage today? How do you see using VSA in your environment? If you’re using VSA already we’d love to hear from you too! Feel free to leave a comment with any questions you may have.
Thanks!
Jeff
Get to know Jeff – Read 10 Questions With… Jeff Eberhard
Brilliant!
This is actually pretty cool. I’ve brought cheap SATA based storage arrays for about 3 thousand dollars and have front ended them with FreeNas or Windows\Linux based NFS. You get the greater number of spindles but it’s still not as good as an entry level SAN for performance and features. I’ve also implemented more expensive white box solutions with FalconStor but that isn’t cheap by far. It’s a nice way to grow into a enterprise class solution.
Hi Keith! FreeNAS/Windows/Linux NFS devices can be great for Test/Dev and non-production environments for sure! My one caveat to that would be that some of those solutions are not officially supported as shared storage by VMware, and while they will likely work, you won’t be guaranteed that VMware support will be able to troubleshoot problems if they occur. I would highly recommend checking out the HCL (http://www.vmware.com/resources/compatibility/search.php?action=base&deviceCategory=san) to verify any storage you’re planning on using for a vSphere environment.
– Jeff
How do you handle hardware maintenance. In other words, how do you put systems into maintenance mode?
Hi Dwight, happy to help here. The VSA Technical Whitepaper (http://www.vmware.com/files/pdf/techpaper/VMware-vSphere-Storage-Appliance-Technical-Whitepaper.pdf) can walk you through putting a VSA into maintenance mode on page 6. Because the cluster mirrors the data, you’re able to still do maintenance on individual hosts in the cluster while providing data access to the remaining members. Hope this helps!
- Jeff