Xen Migration

This afternoon I mostly migrated Xen guests from their old host to their new. (As part of a an upgrade of facilities. Upgrading in place would have been much fiddlier and more annoying!)

The migration took almost three hours, which was longer than anticipated but shorter than I'd feared. In the future I'll know to do it differently, but I managed to script it fairly well after the first couple were done manually.

Everything appears to be working correctly so I will soon nip out for some high quality beer.

One thing that I wanted to do with the new host was track bandwidth usage upon a per-guest basis.

This should be possible with something like vnstat - however solutions counting traffic by interface name are not a good mesh with Xen - since by default a guest will have an interface with a name like 'vif20.0' - and no means of mapping that to a specific guest.

Each of my guests has been allocated three IPs which are defined like this in the Xen configuration file:

vif = [ 'ip=1.2.3.4 1.2.3.5 1.2.3.6' ]

This works prefectly.

This also works:

vif = [ 'ip=1.2.3.4,vifname=foo 1.2.3.5 1.2.3.6' ]

Unfortunately anything else I've tried to give each IP a static interface name fails. I've seen reports of this online but no solutions.

Given a configuration file like this the Xen guest doesn't receive any traffic upon the second + third address:

vif = [ 'ip=1.2.3.4,vifname=foo1',
        'ip=1.2.3.5,vifname=foo2',
        'ip=1.2.3.6,vifname=foo3' ]

Any suggestions welcome.

Tags: lazyweb, xen, xen-hosting | No comments