I think performance and cost are the most valuable features of VMware Virtual SAN. We're stringing up an entire virtualization environment for VDI and RDSH through Horizon View. When we compared the cost of a traditional SAN versus VSAN, that’s what actually made it all possible for us. We're actually able to deploy Virtual SAN for a fraction, like 1/5th, of the cost, of what we're paying for our SAN. It was crazy. The reduced cost made it very palatable and then the actual performance of it made it even that much more functional.
Improvements to My Organization
I'm from the cloud virtualization side of things, so consolidating the data allowed us to set up the VSAN instead of a traditional SAN, and allowed us to do faster deployments without having to interact with as many teams. It's simplified our deployment methodology a fair amount, and it gave us the better performance we're looking for from a SAN perspective.
Beyond that, it didn't change a lot how we function, necessarily, but it gave us a better tool, or a tool specific for our use case, or something that opens up the door for more. I think that the product itself is going to be paramount in other expansions and other aspects of the corporation. We'll likely keep expanding it into general computing and servers across the globe. It might help with some of the other deployments, cache centers and data centers, so that we don't necessarily have to buy SAN. It gives us the performance for the cost that really makes it attractive overall. Beyond that, I don't know.
Room for Improvement
I know it's coming, but I'm really excited for the encryption. I know it's on the all-flash, which is fine, because we're migrating to that anyways. Nonetheless, the encryption would be great for at-rest data, because I don't want to rely on a third party. I don't want to get some self-encrypting drives or anything like that; drives me nuts. That would be very good to get.
I'm looking forward to being able to do VSAN shares with other clusters; sharing the VSAN storage outside of its existing cluster so that we can actually move data a little bit easier between them, or allocate VMs across the entire frame and all the different VSAN storage. I want to try to make more use of the VSAN storage and do some better vMotions across hosts and clusters. That, I think, would be the best.
I like its stability. I think we probably need to get an additional node in there. Right now, we're running some 4-node VSANs. We probably should be at a 5 with a 2-RAID parity on that. Four is okay; it's stable, it's efficient. I haven't really run into any issues with it.
Some of the earlier versions were a little rough; we saw some weird, crooked behavior. Beyond that, it's been solid, and it just works. No issues yet.
Our early deployments of VSAN ran into a few issues with performance. Some of the nodes we installed initially had very high IO utilization when nothing was occurring on the disks; likely related to some replication tasks. Additionally, our fault tolerance was low using just a four-node VSAN (giving an N+1 configuration). We really should be a N+2 (which apparently takes six nodes, not five…).
Performance since then has been outstanding.
We're actually scaling out right now from several 4-node VSAN clusters to - I think we're going to go to - some 8-, and then eventually 12-, node VSANs. That's one of the really nice parts about it; we'll just be able to scale out. The only downside I think I have with it from a scale perspective is, we've got some hybrid VSAN right now. That's what we all started out with. We really liked the all-flash VSAN arrays that you can get, so we're doing that. However, we can't merge the two, so we have to create whole new clusters for the all-flash VSAN. That makes scaling a little bit rough there, but I don't think that will be much of an issue going forward, because flash is pretty inexpensive now and that's probably going to be the standard from here on out.
Customer Service and Technical Support
I think we used technical support earlier on. I didn't personally, but I know our engineers had to work with technical support on some issues with a couple of our VSAN nodes kind of going crazy when they were doing some initial configuration setup. They were just sitting there idle, and one of them would spike up; I don't know if it was trying to replicate data or do something odd. They worked with the support team, got it resolved and addressed it, upgraded to a new version and haven't seen any problems since.
I think there could always be improvement. Whenever we interact with the VMware technical support, it's usually because we have issues that aren't easily solved. We've got our own set of engineers that are really intelligent guys, very capable individuals. Whenever we call in, we always get the initial first line of defense, "Hey, give us your logs." Okay, here's our logs. And then they ask us silly questions and basic troubleshooting and, "Did you do this?" Of course we did. I guess the initial support services guys are just that basic line of defense. They don't always really understand the people that they're dealing with nor have that knowledge of the customer base. That knowledge set they're working with makes it difficult to interact with them a lot of times and getting issues escalated. It's always been kind of a tricky thing for us.
We've been using traditional SAN for a long time. Our engineers had to do test with an initial project to do some developer builds, and they wanted some persistent VMs, and they wanted humongous amounts of storage in them, because they're crazy people. The goal was to give them some virtual machines to replace all these physical machines that they had, because whenever they mess up a machine and they want to rebuild, it takes a long time. You have to rebuild the whole machine, give it back to them, and then they have to build it out all over again.
Using the VDI solution, Horizon View, and VSAN made it actually cost-effective, because if we were try to do the amount of storage that they were looking for on the VMs with traditional SAN, it would have cost us a lot more than anybody's willing to spend or to endure. The VSAN made it very possible and gave us the performance needed to actually facilitate and even perform better on the VMs than they do on the physical boxes that they were using, which is good. It all helped.
Other Solutions Considered
At the time, we did not look into other solutions. It was either SAN or VSAN. From a SAN perspective, we have a partnership with HP for some 3PAR storage, and we have some EMC storage as well. When it comes to VSAN, it was included in our ELA that we agreed with from VMware's perspective. We figured, if we're paying for it, we might as well try using it. It worked out really well.
When selecting a vendor like VMware, a lot of the decision comes down to functionality. Functionality, performance, and cost, those are the usually big factors. A lot of times, my company's really focused on cost, which is a pain in the butt. We're a very big VMware shop to start with, so whenever we can use a product that can simplify deployments, simplify management, and integrate with everything that we already have, that makes it really desirable. That's I think what VSAN did; it really simplified the way for us to get our storage for virtual machines and give us that performance and at a lower cost. That satisfied all the different aspects we look for in products.
I gave VSAN a perfect rating because it's been great. We really haven't had any problems with it; it's been solid. I haven't had to deal with the SAN guys, so that makes my life much better. We get much better performance out of it than I would have ever thought. We get all the IOPS we need from it; we get dedupe on the all-flash array. It's my own little SAN and nobody else gets to mess with. I think it's fantastic. I just love it, I really do.
If you have the budget or it's available to you, definitely go for it, because it's going to save money over the traditional SAN.
The only caveat I ever give to anybody about it is that the initial investments are a little rough. You can't just build a 1-node VSAN; you can do a 2-node VSAN, but, boy, no one ever wants to do it. To really get to a point where you get the data redundancy and the high availability, you need a 4-node VSAN, which can cost a fair amount for that initial investment.
If you're trying to do something small, it doesn't make a lot of sense, but if you're in a larger organisation like we are and you have to do a lot, this is a fantastic tool.
Disclosure: I am a real user, and this review is based on my own experience and opinions.
Sep 08 2016