Why fssnap?

If cannot bring system to "init s" before backing up

ufsdump incremental snapshot (5)

1) fssnap -F ufs -o bs=/var/tmp,unlink /export/home
2) ufsdump 0ufN /dev/rmt/0 /dev/rdsk/c0t0d0s7 /dev/rfssnap/0
* 0 dumps all; N updates /etc/dumpdates with c0t0d0s7 and not rfssnap
3) fssnap -d /export/home
4) recreate snapshot
5) ufsdump 1ufN /dev/rmt/0 /dev/rdsk/c0t0d0s7 /dev/rfssnap/0
* 1 dumps increment against the device specified after N flag

Check ufsdump backup

ufsdump tf /dev/rmt/0

Back up snapshot with tar

1) mount -F ufs -o ro /dev/fssnap/0 /export/bak ; cd /export/bak
2) tar cvf /dev/rmt/0 .

Two facts on snapshots

1) During creation, file system is read-only.
2) File system is consistent, but not application data.

Two ways to list snapshots (brief and long)

fssnap -i
/usr/lib/fs/ufs/fssnap -i

Proper options for snapshots

-o bs=/var/tmp,unlink
* bs -> backing-store file
* unlink automatically deletes the file when not needed

ufsrestore i -> list commands

help

ufsrestore i -> restore now

extract

ufsrestore i -> display added

marked

ufsrestore i -> remove added

delete

/ (root) and /usr need to be restored from

boot cdrom -s

After restoring /(root)

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

Restore only file1 and file2

ufsrestore x file1 file2

List files on tape

ufsrestore t

File used to pass info among incremental restores

restoresymtable

Steps to ufsrestore (5)

1) newfs /dev/rdsk/c0t0d0s7
2) mount /dev/dsk/c0t0d0s7 /export/home ; cd /export/home
3) ufsrestore rf /dev/rmt/0
4) rm restoresymtable
5) ufsdump 0uf /dev/rmt/0 /dev/rdsk/c0t0d0s7
* always back up the new fs - ufsrestore makes changes
* restoresymtable is a temp file for ufsrestore

ufsdump on remote tape

ufsdump 0uf host:/dev/rmt/0 /export/home
* every client must be in ~/.rhosts

Steps to ufsdump /export/home (4)

1) init s
2) umount /export/home
3) fsck /export/home
4) ufsdump

Determine space requirement of ufsdump

ufsdump 0S /dev/rdsk/c0t0d0s0
* S calculates space needed
* useful for incremental backups

Status about the tape

mt status

Five values of tape compression

l low
m medium
h high
c compressed
u ultra compressed

* /dev/rmt/0c uses compression

Two best tapes

DLT - digital linear tape
LTO - linear tape open