IntroductionI'm going to be pretty brief here because I feel I'm not going to have much to actually say about this piece of technology (note from the future: I wasn't able to get this to work in my environment, read on if you're interested in the problems I ran into, but otherwise this article probably isn't worth your time). We'll leave it at : managing Storage IO in a virtualized environment is a pain, so I've taken to investigating some technologies that look at improving storage performance without simply buying more storage devices. This post is written in steam of consciousness style as I go through the setup process. I try to document anything I notice and or am thinking during the install. I do some minimal editing afterwords, but for the most part it'll be a rambling mess.
V-locity is a program from Condusiv, a name that was obviously dreamed up by someone with no respect for spoken language, ease of typing, or autocorrect. Here on I'll probably just refer to it as "the program." The idea behind the program is that windows file system driver is poorly optimized for an age of virtualization and non-local storage. Breaking file read/writes into multiple chunks isn't noticeable on local storage, but can add serious overhead when it has to go over Iscsi. So through a new driver an a bunch of caching, the program hopes to optimize storage to give you better density without buying more hardware (or increasing Cap ex, as they say) </marketing>. I won't go into much of the details of how it works here (I'm still a little fuzzy after a webinar and like 6 sales calls, and let me tell you it's not for lack of paying attention) if you're interested you can read all about it here.
First let me say, Condusiv certainty isn't trying to save you any money over buying more hardware. We were quoted a price of around sixty thousand dollars (+ about seven thousand in yearly licensing) to run on our three servers (32 cores each, which is how it's sold). That's insane, that's roughly three times as much as the server's themselves cost. This more or less makes it only an option if you're out of rack space, or for whatever reason can't move your data to faster storage devices.
SetupI've got a test environment setup. 50 VMs and a server. VMs are running on some Dell R610 servers connecting to their storage over a 6GBs Direct attach SaS link. Server are running XenServer 6.2.0 (sp1 + all other patches). VMs are 64 bit windows 7, all updates installed, basic office applications for testing. Tests will use XenDesktop to measure login performance (connecting via thin clients) and a more manual approach to measure some application launches (visual studio 2012 is one in particular we've had take a really long time to load on VMs due to excessive file system access during first-run)
Setup is broken into three parts, the VMC (controller) and master node (velocity server), and the clients. Since this is a test setup, my VMC and master node are living on the same server. VMC setup is simple, just click next and it installs inself and a webserver to interface from. One thing, it doesn't tell you to access it via the web page. The installer just finishes and you have to figure it out. The setup instructions don't really say this directly either, you just have to kind of guess at it (I figured it out because the install directly had a bunch of .js, .html, etc. files).
After that, the setup runs a discovery on your domain to find machines to install on. I didn't set any sort of filters on this, but it is currently stuck (about 20 minutes) on 740/742, we'll see if it ever finishes.
... 30 minute mark now, still spinning on 740/742.
... well over an hour now. Neither the "close" or "next" buttons do anything.
... two hours and no sign of movement. I'm about to go home, so I'll let it run overnight and reboot the dumb thing if it hasn't sorted itself out by morning.
...Still at the same spot, think it's safe to say it's stuck, going to try restarting the service. Now it says discovery complete, 1 record processed. Sounds legit. Looking through the machine list, it seems to have detected a fair amount of my machines, but none of the VMs I created specifically for testing.
After another restart of the VMC service and some time it picked up all my servers, but I've run into a bigger issue. The master node component won't install on my virtual server. The server meets all of the requirements listed in the various install guides and readme files, but it doesn't show up on the list of machines available for deployment. Trying to run the installer manually gives the error "OS not supported".
Looking further, it is only presenting the option to install the master node component to physical machines. I can't find this listed as a requirement anywhere, and the sales rep/tech people say that it isn't a requirement, but that's the only option it's giving me.
Worked briefly with the sales rep/tech support team that's been helping me, they gave some new licenses to try, but for whatever reason the program still only gives me the option to install to physical servers. I don't have spare physical servers lying around, so we're a bit dead in the water.
On a hunch I looked up Vlocity + XenServer (my hypervisor of choice), and have found some conflicting reports of support for the XenServer platform (PDF). At best it has partial support, and that possibly only for the guest/client. So maybe that's the issue. Looking back through my emails I defiantly mentioned that's what I was running on (and I'm pretty sure we covered that more in-depth during one of the 7-8 phone calls they made me sit through), but maybe I wasn't clear enough.
So, unfortunately this is where it my review of vlocity must end. I'd spend more time with their tech support troubleshooting it, but I have other projects that need my attention. So, take my experiences for what they're worth (probably not much) but if you're looking to evaluate and are using XenServer, maybe be sure you're clear with your reps about the setup.