Virtual Machine memory up by 70%, moving to KVM

Since about 2-3 weeks ago, new virtual machines have been faster!  A lot faster.  That’s because we’ve tweaked our virtual machines to use the excellent Kernel Virtual Machine, finally completing our upgrade from User-Mode Linux which helped start our business six years ago.  For the same money as before you’ll now get 256MB instead of 150MB, 512MB instead of 300MB, 768MB instead of 450MB and 1024MB instead of 600MB.  Disc and bandwidth quotas are remaining the same.  However the underlying technology is more efficient too – I/O bandwidth is much greater, with less work for the host, and we’ve seen loads on our hosts dropping or at worst, remaining constant.  Like so:

Interesting graph showing load drop

That shows a drop in load after moving servers from UML to KVM (graphs from old and new servers spliced together).  It’d be a cheat to say that this is entirely down to the more efficient technology, as we’ve upped the memory allocations by 70%.  Unfortunately I can’t find any particularly recent technology tests to prove our point.  But as a like-for-like commercial comparison it’s fair – you get more RAM for the same price.  And customers have told us it their machines feel faster than they did.

Some VM administrator will already have spotted the upgrade as we’ve been moving servers around.   Others will have to hang on up to 6 weeks while we set up £60,000 of new hosting hardware – but everyone will get the upgrade for free.  The extra hardware will give us the time we need to  move everyone off the old hosts, and on to the new.  If all goes to plan, it won’t be the last improvements to our VM platform this year either.  We’re not happy to sit on our laurels for too long, and once my current round of marketing and recruitment is out of the way, I’m going back to the coal face for a few weeks to improve our VM management.

(sorry, our site still lists the old specifications, but new VMs will get the new specs, and the web site shouldn’t be more than a week from catching up).