[klimenta]

Hi,

Our rootvg ran out of space. Currently we have 2 x 18Gb mirrored HDDs.
We want to upgrade to 2 X 72Gb HDDs. (AIX 5.2-9 running on 7026-6H1).
I want to make sure that everything goes OK when IBM replaces the hard drives.

First I did,

# mksysb -i -v -V /dev/rmt0

to create a bootable backup. I got warning that boot image is larger than 12Gb, but I verified that I have IY53546, IY56839 and firmware is CM060505.

Once they replace the hard drives, I'll boot from tape and restore the backup. After that I'll use # extendvg and increase the volume groups and then file systems (JFS) on fly.

Is there anything that should concern me? Any experience?

Thanks a lot...

[rbinkl]

Here are the steps if root vg is mirrored. :

Unmirror rootvg
Remove hdisk1 from rootvg
rmdev -l hdisk1 -d
cfgmgr
Verify hdisk1 now has the new size
Add hdisk1 to rootvg
Mirror rootvg
sync AND WAIT TO COMPLETE
Redo for hdisk0

[klimenta]

This steps should be performed after I restore the tape on new drives? Right?

Thanks...

[schnupfy]

no, if your SCSI Controller is hot plugable you don't need to reboot. You could do these steps with the running system and application.

[klimenta]

Unfortunantely, the drives are internal and not hot plugable.

[schnupfy]

which is not a problem, so you just do these steps (described by rbinkl)
Unmirror rootvg
Remove hdisk1 from rootvg
rmdev -l hdisk1 -d

SHUTDOWN, swap hdisk1, BOOT

Verify hdisk1 now has the new size
Add hdisk1 to rootvg
Mirror rootvg
sync AND WAIT TO COMPLETE
Redo for hdisk0

so you need 2 reboots. Do the mksysb as a backup, but usually you don't need it.

Cheers.

[babylonrocker]

and don't forget to fix bootlist and bootimage

for the bootimage use
bosboot -ad /dev/hdisk0 ... and hdisk1
for the bootlist
bootlist -m normal hdisk0 hdisk1

bye

[Chapter Eleven]

FYI: You cannot add a 72G drive to a rootvg built on 18G's.

The original install would have set the PP size on the 18G's to get as close to 1016 PPs per PV as possible, and a 72G would have way more than that per drive if added via extendvg.

The last time I tried to do a chvg on a rootvg to adjust the factors that control that, AIX (5.3) laughed at me and said go away. (I was doing the exact same thing only with virtual hdisks served up by a vio server).

mksysb or clean install. Personally I favor the latter as mksysbs are almost always messy.

[Frans]

There is an underlying problem that I can see in your system. If your rootvg has grown to this size you need to look at what is taking up all the space
Things to do
1. Go into all the files in rootvg and find out what the biggest files are and see what they are used for.
2. Look for core dumps and junk and remove them
3. Have a look in /var/preserve for any files you can remove
This relates to vi that was broken out ( man vi -r )
4. You should have no application filesystems in here at all
5. remove any old dumps snap and other old logs
6. Limit syslog to a rotate of 9 files have a look in syslog directory see how many files. remove old once add this sort of line to syslog to enforce this
At the end of the last entry in syslog add rotate time 1d files 9
7. Remove any old devices you have in AIX install that is no longer required

8. Have a look at the size of your wtmp
Cd /var/adm
To clear this file use /usr/sbin/acct/nulladm wtmp
9. Look in /var/adm/ras for old big logs that can be cleared
This cleared a lot of the space taken up in rootvg and will make your boot image much smaller.

Happy system cleaning