Filesystem Reduction?

[Roomer]

Anybody reduced a filesystem size (v 4.3.3.0) ??

Any info would be appreciated..

Roomer

 

[samizdat]

I've used both procedures below many times without a problem. Good luck!

If there is not enough free space on the disk(s) to have both filesystems allocated, use the first procedure...

1. Backup to a tape drive if one is available. Use the backup command.

monkey:root:/#> /usr/sbin/backup -f/dev/rmt0 -0 /usr/local

2. Unmount and remove the filesystem. (Verify your backup first)

monkey:root:/#> umount /usr/local
monkey:root:/#> rmfs /usr/local

3. Recreate your logical volume and file system with the smaller size.

monkey:root:/#> mklv -y hd99 -t jfs rootvg 24 hdisk0
or use SMIT: 'smitty mklv' to create your logical volume and
'smitty crjfslvstd' to create your smaller jfs filesystem on top of the previously created logical volume.

4. Mount your filesystem.

monkey:root:/#> mount /dev/hd99

5. Restore from you tape backup

monkey:root:/#> /usr/sbin/restore -rq -f/dev/rmt0 -d/ -v

or use the 'smitty restfilesys' fastpath.

|----------|-----------|----------|-----------|----------|
|----------|-----------|----------|-----------|----------|

Secondly:

BTW, if you are not mirrored you should ignore the first step and Step 8.

The process assumes that you have a moderate size JFS filesystem on hdisk2, and a mirrored copy on hdisk3:


1. Break mirrors:

rmlvcopy fslv.old 1 hdisk2

2. Create new filesystem (fs.new) on free hdisk at a smaller size:

smitty lv
Create the fs.newlv:

smitty fs
Create the JFS fs.new:

mount fs.newlv

3. tar fs.old to buffer, and untar to target fs.new without tmpfile:

cd /fs.old

This tar command has the potential to destroy existing data in the event of typographical errors. It is recommended to precede it with a # to comment it out, then recall and check for accuracy prior to actual execution:

#tar -cvf - .|(cd /fs.new;tar -xvpf -)

tar -cvf - .|(cd /fs.new;tar -xvpf -)

4. Check the results to ensure the copy was correct:

ls -alR /fs.old > fsold
ls -alR /fs.new > fsnew
diff fsold fsnew (should be none of note)

5. Reorg filesystem:

umount /fs.old
umount /fs.new

chfs -m fs.old.flag fs.old (rename orig fs.old to fs.old.flag)
This changes the mountpoint of the old filesystem freeing the original:

chfs -m fs.old fs.new (rename new fs to old fs name)
This changes the mountpoint of the new filesystem to the original one:

mount /fs.old.flag
mount /fs.old (The new smaller JFS is here now)

6. Check the results to ensure correct copy:

ls -alR /fs.old fsold2
diff fsold fsold2 (should be none of note)

7. When assured that both filesystems are the same, remove original filesystem:

umount /fs.old.flag
rmfs -r fs.old.flag

8. Remirror the new, smaller filesystem:

mklvcopy -k fs.oldlv 2 hdisk3

9. End up with:

/dev/fs.newlv /fs.old

10. Rename the lv and complete the switch:

umount fs.oldlv
chlv -n fs.oldlv fs.newlv

remount

mount /dev/fs.oldlv

11. The change is now complete, and you should see a smaller sized JFS with the old name and mount point:

/dev/fs.oldlv /fs.old

 

[samizdat]

Sorry, but I for got the step to create the filesystem from the command line. (Step 3) After creating the logical volume. It should be:

monkey:root:/#> crfs -v jfs -d hd99 -m /usr/local -A