New Years eve the extra bits of hardware I needed for my Xen box arrived (cheapo motherboard for VMX (Intel VT-x in my case) and power supply). As you can imagine with a house full of people, and corresponding day of pain afterwards, it wasn't the best time to be faffing with setting it all up. However, a few days later and it's all there and working like a dream.
I have to say that I'm pleasantly surprised and also taken back by a few things. I'm also a little disappointed about a few bits and bobs, but I'll get to that later.
Having tested Xen previously, and having got a book on it for quick reference, getting it set up was painless, quick and easy, once I'd upgraded my dom0 to Lenny to sort a few networking and Xen related issues. Whilst I maybe a glutton for punishment for running without a GUI, I actually found setting up both Linux and Windows virtual machines painless from the command line.
One thing I was worried about, was the performance of the Windows machines I'd setup - they were awful. I really do mean it. It was like being back in front of the AMD box that we were using for virtual machine testing at my old job 3 or 4 years ago. Turns out that Windows XP/2003 and the Xen ACPI implementation don't quite play nicely and it's a case of making Window use the “standard pc” “drivers”. Once I'd done this it was a hell of a lot better.
Continuing on the subject I was also a little apprehensive of using LVM2 in my setup, as last time I'd used it I'd ended up with mangled data. Since it's now been quite a while since that happened (years now), the fact that it's very widely used, and on mention from Andy that he'd been using it at work for super secret projects, I went for it again. Happily there's been no problems and the disk performance of the domU's is excellent.
Xen has also given me my first real opportunity to use and play with Vyatta, a fully pre-packaged, commercially supported, open source alternative to Cisco, Juniper, etc. It's actually pretty sweet, it must be said. I like the JunOS-like interface for setting it up, and how the config needs to be saved and commited, and how it's all accessible from the command line or web-GUI (if you're that sort of person). If you're already using your own rolled Linux boxes as routers, then you might not beable to see the point behind Vyatta, and I must admit before trying it I was one of those people. However, it's simply that it's all there already, with support should you need it - which in the real world can sometimes be very useful (as I'm sure everyone knows, since people like Redhat, Canonical, IBM, etc. exist and thrive). As time goes on I hope to not only use it in testing, but also for creating a quarantined portion of my personal network here, and to connect the other “main house” network. Hopefully that'll work out nicely, and if I does I may well end up using Vyatta on my next externally hosted server (which may end up being setup in a xen-hosting style - let me know if you maybe interested!).
The only shame with the Vyatta system, is the price of the hardware appliances from the commercial company. In comparison with Cisco's offering they are cheaper, but when you're looking at the small end of the companies we support at work, it's sometimes hard to justify using anything more than a really cheap Draytek or “worse”.
So on the whole things are going well with Xen. Right now I don't know if I'd suggest a Windows 2008 Hyper-V Core server or Xen at work, next time it comes up - I suspect that I'd suggest different solutions for different circumstances (i.e. Hyper-V core for a Windows network with non-virtual AD boxes, and Xen for a colocation setup), but I can't really explain why when you exclude the obvious (such as managability in each situation). Food for thought perhaps
Apparently I need to say Happy New Year also.