As a good old saying says – An Apple a Day keeps the Doctor away – is also applicable on having good OS backup that will always keep headaches lesser when the hard times come. Now comes ufsdump, a usefull command to help us backup our Solaris Operating System.

Based on the man pages of ufsdump(1M):

ufsdump backs up all files specified by files_to_dump (usually either a whole
file system or files within a file sytem changed after a certain date) to
magnetic tape, diskette, or disk file.

The ufsdump command can only be used on unmounted file systems, or those
mounted read-only. Attempting to dump a mounted, read-write file system might
result in a system disruption or the inability to restore files from the
dump. Consider using the fssnap(1M) command to create a file system snapshot
if you need a point-in-time image of a file system that is mounted.

If a filesystem was mounted with the logging option, it is strongly
recommended that you run ufsdump as the root user. Running the command as a
non-root user might result in the creation of an inconsistent dump.

Here are the steps for us to utilize this command given that our root (/) partition resides under c0t0d0s0:

It is recommennded to put our system on Single User Mode:

root@solaris# init -s
or
roo@solaris# reboot -- -s

Check the partition for any inconsistencies:

root@solaris# fsck /dev/rdsk/c0t0d0s0

Insert the tape into the drive and verify:

root@solaris# mt -f /dev/rmt/X stat (where X is the drive number)

Back up the system:

root@solaris# ufsdump 0uf /dev/rmt/0n /