Change out OS disks in large database system

[Philip Kernohan]

Scenario:

Large server connected via 8 FCs to disk array which has a Oracle database residing on it.

OS disks are currently 4GB and located in a mini-disk array separate from the larger array.

We need to move the OS from the non-mirrored 4GB drives (bad planning I know) to mirrored 18 GB drives.

We have to ensure that all of the database remains intact and hence all the devices etc. that Unix sees remain the same in the large disk array to allow the Oracle datafiles to function.

If we take an ignite backup will this go back onto the 18 GB drives with no further changes required?

Should I leave the database disk array attached, via the FCs, during the entire process or is there any possibility that this array could be a problem?

In short - would the following steps be correct?:
1) Ignite backup the entire OS filesystems
2) Shutdown & power off
3) Remove 4GB drives
4) Power up
5) Ignite from ignite backup
6) Startup Oracle

[Charles Harris]

Hi,

Don't take this as gospel but.... In the past, to achive this we have downed the oracle DB (ALL) and then backed up the files using your fav. backup soloution as the DB resides on a normal filesystem.

I don't know wether an ignite 'image' will try to replicate the data deeper than the normal filesystem level, ie like a ghost image of the entire disk, or wether it will work.

If in doubt, tar and gzip it up and then explode it back on the new disks.

Good luck!

-ChaZ-

[Patrick Wallek]

If you 4GB root disks are all in VG00 and you FC attached disk arrays are all in another VG then you should be OK.

The process that I did when going from 2GB root disks to 18GB was:

1) Backup my data
2) Make the make_recovery tape so I get my backup software DB too
3) Bring down system
4) Attach 18GB drives - I left the 2GB drives attached just in case the make_recovery tape missed something
5) Boot from the make_recovery tape, point the install to the 18GB drive and let it fly.
6) System reboots. Bring up DB (not oracle) and test.
7) Mirror the root disk
8) Reboot and boot from mirror to make sure it works.

[James R. Ferguson]

Hi Philip:

Your plan looks sound. Personally, I'd make two Ignite 'make_tape_recovery' tapes before I started with current Ignite software.

...JRF...

[Victor BERRIDGE]

Hi Philip,
You shouldnt have any problem with your procedure, but since your old OS disks are on a mini disk array, do you have to remove them?
This is how I understand your config and so how I would do:
2 subsystems, one OS one app/data

1) vgexport vgX[y-z] to mapfiles, for safety purpose copy them with /etc/fstab on another box also
2)make_recovery
3) add if possible the new disks
4) Reboot and interact with IPL
reinstall OS with new values on new disks
5) reboot
6) vgimport from mapfile
7) tes if all is OK

All the best

Victor

[MARTINACHE]

Hi,

An other solution :

- Mirror your 4GB on your 2 18GB
- remove lvol from your 4GB
- remove your 4GB from vg00

If need to extend FS from vg00, then

- do an ignite tape
- restore from ignite with FS modifications (ignite will automaticaly choice the 18GB disks)

Regards,

Patrice.

[Patrick Wallek]

The mirror solution is probably not the best. The problem you will run into is that your MAX PE per PV amount is probably just large enough to accomodate the 4GB disks, and if you add the 18GB into the VG, you'll be able to use only 4GB out of 18GB. Probably not what you were looking for.

To get around the MAX PE per PV problem you'd have to go through the steps you are going through anyway with the make_tape_recovery tape as that is the only way to change MAX PE per PV.

[Shahul · Accepted solution]

Hi

Mirroring to 18GB is the easyestway I think. But If U want to increase the LVs in VG00, I will give one procedure..
I hope U have free 18 GB HDD in disk Array.

#pvcreate -B -f "raw device file"
#mkdir /dev/vg01 (If vg01 does not exist)
#mknod /dev/vg01/group c 64 0x010000
#mkboot raw device file (Please find man page of mkboot)
#mkboot -a hpux raw device file
#vgcreate /dev/vg01 "Block device file"
#lvcreate -L xxx /dev/vg01
xxx is size of new boot volume
#lvcreate -L yyy /dev/vg01
yyy is size of new primary swap
#lvcreate -L zzz /de/vg01
zzz is size of new root volume
#newfs -F hfs /dev/vg01/rlvol1
#newfs -F vxfs /dev/vg01/rlvol3
#lvlnboot -b /dev/vg01/lvol1
#lvlnboot -r /dev/vg01/lvol3
#lvlnboot -s /dev/vg01/lvol2
#lvlnboot -d /dev/vg01/lvol2
#lvlnboot -v
Now it should show the listing of two HDDs lvs.
#mkdir /newboot
#mkdir /newroot
#mount /dev/vg01/lvol1 /newboot
#mount /dev/vg01/lvol3 /newroot
#cd /
#find . -xdev -depth -print | cpio -pxdm /newroot
#cd /stand
#find . -xdev -depth -print | cpio -pxdm /newboot
#cd /newroot/etc
change primary boot path to new 18GB hDD by using setboot command.

edit fstab as per ur requirment.
Shutdown the system. Remove the 4GB HDDS and reboot.

This should work

If U don't want to change LV sizes U don't want to do all this.

Best of luck
Shahul

[Eileen Millen]

I went from 2 4Gb mirrored disks to 2 18Gb disks using make_recovery and help from HP.
make_recovery was run in preview mode to
make a configuration file. The disk size
was changed in the config file. Then the make_recovery tape was created. HP support provide me some command lines to add to a post recovery script file to do the mirroring again after the recovery.
I had problems when my /var directory filled up and had to use another disk. This was about a year ago. Ignite is better now.
It might be best to call HP for input.
Good Luck.
Eileen