Recovering a root disk and root mirror from backup tape

I assume here that you already have the below information as backup data.

• A listing of the partition table for the original root disk before you brought the disk under Volume control (ZFS,  VXVM).
• Backup of complete root disk using any command like (UFSDUMP, cpio, etc)
• A new boot disk installed to replace the original failed boot disk if the original boot disk was physically damaged.

Assuming the replaced disk address as c0t0d0s2

Here are the steps to perfom.

1.  boot cdrom -s
2. Create the partitions which should be identical to the slice specifications of replaced disks (VTOC).
3. mkfs -F ufs /dev/rdsk/c0t0d0s0 (create the filesystem)
4. Mount/dev/dsk/c0t0d0s0 on a suitable mount point such as /a or /mnt (mount /dev/dsk/c0t0d0s0 /a)
5. restore the backed up data (use ufsrestore if used ufsdump).
6. then install the boot block using installboot command.

Similarly follow the process if you have separate filesystems for var and usr.