I've got my Ubuntu 13.04 install backed up to my external hard drive using deja-dup. I formatted the drive with lvm so I could use the rest of the drive for external storage while having the resize capeabilites of an lv. When I plug the drive in to backup, it mounts and runs properly. Backup's done, I hit the eject button to unmount the backup lv, everything still green. I unplug the drive, noting the activity light is on but doesn't go off.
After doing this I want to access the storage, so I plug the drive in but get an error which reads:
Unable to access “storage” Error mounting /dev/dm-2 at /media/alex/storage:
Command-line `mount -t "ext4" >-o "uhelper=udisks2,nodev,nosuid" "/dev/dm-2" "/media/alex/storage"' exited >with non-zero exit status 32:
mount: wrong fs type, bad option, bad superblock >on /dev/mapper/VG1-storage,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
I've messed around Linux and the command line long enough to know it's not mounting properly because it wasn't unmounted properly, but after a couple of week's worth of searching and hacking I'm still resorting rebooting in order to fix it. What's the procedure to "unmount" a physical volume?
vgchange -a n /dev/vgname
)?