Thanks for the help so far. The second command you sent fails. To setup a raid1 I did 0 160000 mirror disk 3 /dev/hdb1 2048 sync 2 /dev/hdb2 0 /dev/hdb3 0 What's the meaning of the 2048? Your example had 64. Is that the number of sectors per bit in the bitmap? If not, what? Is there any way I can tell how the 'sync' daemon is progressing? It seemed to startup these kernel threads. [kmirrord/0] [kcopyd] I could mkfs and mount the file system. Cal Page