Comment 3 for bug 292223

Experienced the same problem and trials as the original poster. I didn't know about the --no-migration-assistant option, so i just ran on a console "grub-install --root-directory=/target/ /dev/sda" and will now reboot (i'm writing this while still on the live cd).

migration-assistant, from what i could check on the syslog, died because it couldn't umount the home partition (mounted on /mnt/migrationassistant)

Nov 19 14:01:57 ubuntu ubiquity[8220]: InstallStepError: MigrationAssistantApply failed with code 2

before, in the logs, these messages appeared:

Nov 19 14:01:40 ubuntu os-prober: debug: os detected by /usr/lib/os-probes/mounted/40lsb
Nov 19 14:01:40 ubuntu ubiquity: mount: /dev/mapper/lvmvol-home já montado ou /mnt/migrationassistant ocupado
Nov 19 14:01:40 ubuntu ubiquity:
Nov 19 14:01:40 ubuntu ubiquity: mount: de acordo com mtab, /dev/mapper/lvmvol-home já está montado em /mnt/migrationassistant
Nov 19 14:01:40 ubuntu ubiquity:
Nov 19 14:01:40 ubuntu migration-assistant: error: Failed to mount /dev/mapper/lvmvol-home
Nov 19 14:01:40 ubuntu ubiquity: mount: o ponto de montagem /mnt/migrationassistant/home não existe
Nov 19 14:01:40 ubuntu ubiquity:
Nov 19 14:01:40 ubuntu ubiquity: umount: /mnt/migrationassistant: device is busy.
Nov 19 14:01:40 ubuntu ubiquity: (In some cases useful info about processes that use

hope that helps.
Thanks!