Restoring the root filesystem on Solaris

Restoring theroot (/) File System

To restore the / (root) file system, boot from the Solaris CD-ROM and then run ufsrestore.

If / (root), /usr, or the /var file system is unusable because of some type of corruption the system will not boot.

The following procedure demonstrates how to restore the / (root) file system which is assumed to be on boot disk c0t0d0s0.

1. Insert the Solaris 8 Software CD 1, and boot the CD-ROM with the single-user mode option.

ok boot cdrom -s

2. Create the new file system structure.

# newfs /dev/rdsk/c0t0d0s0

3. Mount the file system to an empty mount point directory, /a and change to that directory.

# mount /dev/dsk/c0t0d0s0 /a
# cd /a

4. Restore the / (root) file system from its backup tape.

# ufsrestore rf /dev/rmt/0

Note – Remember to always restore a file system starting with the level 0 backup tape and continuing with the next lowest level tape up through the highest level tape.

5. Remove the restoresymtable file.

# rm restoresymtable

6. Install the bootblk in sectors 1–15 of the boot disk. Change to the directory containing the bootblk, and run the installboot command.

# cd /usr/platform/`uname -m`/lib/fs/ufs
# installboot bootblk /dev/rdsk/c0t0d0s0

7. Unmount the new file system.

# cd /
# umount /a

8. Use the fsck command to check the restored file system.

# fsck /dev/rdsk/c0t0d0s0

9. Reboot the system.

# init 6

10. Perform a full backup of the file system. For example:

# ufsdump 0uf /dev/rmt/0 /dev/rdsk/c0t0d0s0

Note – Always back up the newly created file system, as ufsrestore repositions the files and changes the inode allocation.

Restoring the /usr and /var File Systems

To restore the /usr and /var file systems repeat the steps described above, except step 6. This step is required only when restoring the (/) root file system.

To restore a regular file system, (for example, /export/home, or /opt) back to disk, repeat the steps described above, except steps 1, 6, and 9.

Example

# newfs /dev/rdsk/c#t#d#s#
# mount /dev/dsk/c#t#d#s# /mnt
# cd /mnt
# ufsrestore rf /dev/rmt/#
# rm restoresymtable
# cd /
# umount /mnt
# fsck /dev/rdsk/c#t#d#s#
# ufsdump 0uf /dev/rmt/# /dev/rdsk/c#t#d#s#

courtesy of http://www.kobhi.com/solaris/backup_recovery/solaris_backup_root_restore.htm