Changing Disks

[Tiago Marques_2]

Hi!

I've four 18Gb HD installed in a L2000 server. Two of them have HP-UX installation and another two have data files. I'm intended to expand the data storage space, changing the two 18Gb data disks by two of 36Gb. What do you understand to be the best way to realize this change? I already have the backup recorded, so Can I remove the actual data LVols then remove the old disks and recreate that in the new disks?

Thanks!

[James R. Ferguson]

Hi:

Since your volume groups were probably created with default 'max_pe' values (i.e. no explicit value was given, and the size of the physical disk at 'vgcreate' was used) you probably will not be able to utilize all of the new 36GB extents.

You can use this to make your Ignite tape and to boot from it:

# make_tape_recovery -x inc_entire=vg00 -I -v -a /dev/rmt/0mn

When you boot from this tape, you will have an interactive recovery.

Therefore, make an Ignite recovery tape and reinstall your server. This accomdates the up-sizing for vg00. Then, for non-vg00 volume groups, recreate the volume groups and load your data to them.

Regards!

...JRF...

[Arockia Jegan]

Hi,

I guess you have only internal drives. Unmount the file systems residing in that two drives.
Make sure that drives are not used by any application/processes.
#umount
...
..

Are those drives under vg00? If not,

#vgchange -a n y /dev/vg??

#vgexport /dev/vg??

Replace the drives..
#insf -e disk

Create the volume group/ logical volume/ file system and restore from the backup.

Before doing this activity make a ignite tape.

[MANOJ SRIVASTAVA]

Hi Tiago

I understand you ahve 4*18 GB and want to remove 2 *18 GB to replace with 2 *36 GB disks
, please take backup of the data disk and restore it on the new disks for theis the only thin you ened to do is :

1. Take backup.
2. Vgexport the data vg's
3. Replace the new hdd's
4. Create same volume groups.
5. Restore Data from the tape.

Also please spread the data amongst the VG's so that there is good repsonse.


Manoj Srivastava

[PIYUSH D. PATEL]

Hi,

There is no need to remove the lvols from the disk. You need to vgexport the volume group contanining those disks ( eg vg01 ).

Unmount filesystems,then
vgchange -a n /dev/vg01
vgexport -m /tmp/vg01.map /dev/vg01

The add the new harddisks, if the device files are not created, create it with
insf -e

Then create a new volume group and logical volumes with the new disks.

Mount the logical volumes and then restore your data back.

Piyush

[Tiago Marques_2]

Hi!

I don't have the package MC Service Guard. Is there any problem to perform the vgchange without that?? Or can I perform only the vgexport and not vgchange??

After insf -e, the new disks will be recognized with 32Gb??

Thanks!

[Arockia Jegan]

Why do u require MC service guard? You need to use vgchange to deactivate the volume group. Then only you will be able to run vgexport.

#vgchange -a n /dev/vg??

[PIYUSH D. PATEL]

Hi,

You dont require MCSG fro doing lvchange. lvcgange is used to deactivate the volume group so that you can export it using vgexport command.

Incase the system does not create the device files then you have to use insf -e. It will detect the 36GB disks also.

Piyush

[Bart Beeren]

You don??t need MC Service Guard for the commands mentioned by the others. You only need LVM.

I hope you do mean that you have put your data in a separate vg and not in a lvol in vg00? However, if you do have this, it is wise to create a data-vg (vg01) for your data.

If you have a GOOD backup of your data and you have unmounted your data-vg/lvol, you can just perform a vgremove/lvremove of the data-vg/lvol. Then replace the 18 GB hdd??s by the 36 GB hdd??s and recreate/create the data-vg with the new characteristics. (You can do these actions also by the use of SAM) After performing these actions it is time to restore your data into the new data-vg.

If you buy a 9 GB hdd you are only able to use approximately 8 GB of it. For a 18 GB hdd it is only 16 GB anf for yours 36 GB it is only 32 GB. There seems to be a pattern (always 1 GB is lost per 9 GB) but the reason for it I do not know :-(

BB

[Jordan Bean]

Another suggestion I have requires the disks to be mirrored. Is this so?