During a recent update of a number of Xen Guests, one of the machines would not come up again. The boot log showed the following:
.... [ 1.548101] udevd version 128 started [ 39.838865] kjournald starting. Commit interval 15 seconds [ 39.838871] EXT3-fs: mounted filesystem with ordered data mode. [ 41.462902] udevd version 128 started [ 41.642193] rtc_cmos rtc_cmos: rtc core: registered rtc_cmos as rtc0 [ 42.007710] Adding 257000k swap on /dev/xvda1. Priority:-1 extents:1 across:257000k SS [ 43.498944] BIOS EDD facility v0.16 2004-Jun-25, 0 devices found [ 43.500097] EDD information not available.
It turned out, that the reason for this were some errors in the root filesystem although the filesystem itself was marked clean, and could be mounted without problems.
An easy way to solve this is as follows:
- Attach the device to Domain-0 with
xm block-attach Domain-0 <block-device> xvda w
- e2fsck -f -y /dev/xvda? (with ? being the right partition)
- Detach the device
xm block-detach Domain-0 xvda
After this the guest came up without any problems.