I got dozens of errors like ---------------------------------- Dec 2 04:21:39 alfred kernel: EXT3-fs error (device dm-3): ext3_free_blocks: Freeing blocks not in datazone - block = 18318 17304, count = 1 ---------------------------------- the other day. I guess dm-3 means my 3rd LVM volume, which is /tmp . But how does one tell what dm-? corresponds to?