Do any of you use Xen?

Not meaningfully. The market has moved a LOT since I last used it.

We've got a guy who insists on using Xen for some live VM's but they VM's just randomly dissapear

Like today we lost a production SQL server, he's the only one who can recover it, and he's busy dropping his kids off at school

Ow.

We're in the process of getting rid of him, for this exact reason, but it's been a 15-year relationship between the company and him

So extracting him is...... difficult

Yeeaah. People like that grow tendrils into everything.

I'm sure that this is not normal behaviour for a mature hypervisor though

He must have done something really messed up

Last I checked there were a couple of types out there. An open-source version, and the professional one Citrix sells.

I'm seeing a good amount of Xen in marketplace, I'd say just barely third to HyperV. However, on the OSS side KVM has eaten Xen's lunch AND kicked its teeth in.

Yeah this is the free version

Which is apparently always one major version behind the commercial one

The last version I touched was 3.12 or somesuch.

I'm not familiar with KVM, but I tried to do some interrogation of Xen a few months ago

Tried to get some IO stats from the VMs

they just don't exist

It was virtually impossible to find which VM was consuming all the disk access, or troubleshoot access issues

Yeah xen top gives some info, but not the kind you'd need to do a serious eval.

I'm a bit spoilt though because VMWare just makes it all so damn easy

Especially with VCenter. Oh my the statistical goodness.

Damn straight

The overnight Exchange online defrag shows up like a mesa on the charts. Then we spread 'em around to better save wear on our storage.

VMotion with DRS is a life saver too

I did a fibre-channel switch firmware update a month ago. We managed to not have any significant downtime thanks to just that. I was up until 6am but we had no major service outages.

When someone generates a report in a TS with a range they shouldn't (say 10 years of data), everything else moves out of its way, and then comes back when its finished

Ah we don't have VMotion Storage, but because of MPIO they're usually pretty smooth

We do have one app though that cracks the shits every time it migrates though, it's a broker for an IIS plugin. It's a bit of an odd one out, but thankfully VMWare even allows you to set VM-specific migration settings

I almost creamed my pants when we ugpraded to enterprise

I was moving hosts around so I could rob individual ESX hosts of their storage connectivity. MPIO helps for some of it, but sadly not all.

Our Exchange mailbox servers are like they. Their RAM requirements are large enough that it makes the migration take long enough for the hiccup to be noticed.