A small PSA: If you are upgrading Ubuntu to 7.10 “gutsy”, check to see if you have the “evms” package installed. If you do, and you have no knowledge of installing it and don’t know what it is, then you probably should remove it. The consequences of keeping it are a spew of system messages:

device-mapper: dm-linear: Device lookup failed
device-mapper: error adding target to table

Even worse, you may be unable to mount any partitions aside from /! That’s what happened to me. 🙁

There are lots of people having these device-mapper errors. Some explanation is given in the “Volume activation” section of the EVMS FAQ.

If you run into the problem where you reboot and no longer have a /var partition, you should try preventing evms from starting at boot and rebooting. For example, you can do this:

mv /etc/rcS.d/S27evms /root

If your system doesn’t want to reboot, check for processes hung up on shutting down (I had to kill off something related to Alsa). If everything comes up fine, clean and purge:

mv /root/S27evms /etc/rcS.d
aptitude purge evms

Everything should be happy at this point. You can also clean up the junk that ended up in /var when your /var partition couldn’t be mounted. Just mount / to another place, clean and unmount. Thanks to Ross Cohen for telling me about multimount1.

  1. “Since Linux 2.4 a single filesystem can be visible at multiple mount points” —mount(2) man page↩︎