SUMMARY:Mirroring a disk with dd

From: Marz Consulting Inc. (
Date: Thu Apr 27 2000 - 10:39:39 CDT


Can anybody tell me if using dd is OK to use to backup a disk? Here's my
situation. I have a sparc20 running Solaris 7 with all patches and 256 meg
of ram. I have two 2 gig drives. My requirement is to back up the first disk
ocassionally to another harddrive and be able to boot from the second
drive just like it was the first drive. Tape is not an option. I must mirror
from the first drive to the second one. Thoughts? TIA/Will ummarize.


dd is fine but I need to watch a few things.
1. make sure to use the fmt_hard to make sure that the partitions
   are identical to avoid data loss due to ill defined partition boundaries.
2. Be aware of the need to edit the vfstab
3. use the devalias command to create a devic alias to the new drive
    so you don't have to mess with the long device name when booting from
     the alternate disk.
4. Install the bootblock with installboot
/usr/platform/`uname -i`/lib/fs/ufs/bootblk /dev/rdsk/c0t1d0s0
   (use device name as appropriate)
5. dd will copy the bad blocks to the new disk.

Thanks to all 45 who responded !


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