We recently had a few power outages at work, some scheduled, some not, and this played havoc with our xen servers.

One of the problems we had was that xend would not start (and thus xendomains would also not start).

Checking /var/log/xen/xend.log gave us the following snippet:

<br /> inst = XendNode()<br /> File "/usr/lib/python2.5/site-packages/xen/xend/XendNode.py", line 164, in __init__<br /> saved_pifs = self.state_store.load_state('pif')<br /> File "/usr/lib/python2.5/site-packages/xen/xend/XendStateStore.py", line 104, in<br /> load_state<br /> dom = minidom.parse(xml_path)<br /> File "xml/dom/minidom.py", line 1913, in parse<br /> File "xml/dom/expatbuilder.py", line 924, in parse<br /> File "xml/dom/expatbuilder.py", line 211, in parseFile<br /> ExpatError: no element found: line 1, column 0<br /> [2008-03-10 21:37:40 18122] INFO (__init__:1094) Xend exited with status 1.<br />

We run a lot of Xen instances for our development and test servers and a few were starting to get full. Fortunately the disks in the real servers were very large and the xenlet partitions were made using LVM so resizing them to add more space was possible!

root@dev-myfiles0:~# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda1             4.0G  3.8G  200M  95% /
varrun                257M   48K  257M   1% /var/run
varlock               257M     0  257M   0% /var/lock
udev                  257M   40K  257M   1% /dev
devshm                257M     0  257M   0% /dev/shm

Basically we just have to shut down the xenlet, resize the partition and then restart the xenlet again, simple!