Comment 10 for bug 559582

Likewise, this affects me too, karmic->lucid beta on a virtual machine, /etc/fstab:
proc /proc proc defaults 0 0
/dev/xvda / ext3 noatime,errors=remount-ro 0 1
/dev/xvdb none swap sw 0 0

# mountall
swapon: /dev/xvdb: swapon failed: Device or resource busy
mountall: swapon /dev/xvdb [11712] terminated with status 255
mountall: Problem activating swap: /dev/xvdb

# do-release-upgrade -d
.....
.....
Upgrading
Done downloading
Exception during pm.DoInstall(): E:Internal Error, Could not perform immediate configuration (2) on mountall

Could not install the upgrades

Error during commit
'E:Internal Error, Could not perform immediate configuration (2) on
mountall'
Restoring original system state