topic Re: Disk replacement in Operating System - HP-UX

Disk replacement

Rkumar — Sun, 21 Feb 2010 05:30:08 GMT

Dear Experts,

Recently I have done disk replacement activity. And the activity completed successfully. the disk that need to be replaced was alternate disk of root volume group as well hot swapable.I followed the below mentioned procedure.

1. pvchange -a N /dev/dsk/c#t#d#
2. FE will replace the disk
4. vgcfgrestore -n vg00 /dev/dsk/c#t#d#
5. pvchange -a y /dev/dsk/c#t#d#
6. vgsync vg##
7. shutdown -ry 0
8. mkboot -l /dev/rdsk/c1t0d0
mkboot -a "hpux -lq" /dev/rdsk/dev/rdsk/c1t0d0
mkboot -b /dev/rdsk/c3t0d0 /dev/rdsk/c1t0d0
lifcp /dev/rdsk/c1t0d0:AUTO –
lvlnboot -R

In this procedure I did not use pvcreate -B (this could be 3rd step).please let me know that without creating a physical volume on a disk can it used in a VG.?

Thanks,
Rahul

Re: Disk replacement

Johnson Punniyalingam — Sun, 21 Feb 2010 05:34:02 GMT

Please refer to HP offical document on Disk replacement .. :)

"Good disk Gone Bad".

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad_WP.pdf

Thanks,
Johnson

Re: Disk replacement

Rkumar — Sun, 21 Feb 2010 06:07:42 GMT

Thanks Johnson

I appreciate u r quick reply however my concern is that in this procedure I did not use pvcreate -B (this could be 3rd step).please let me know that without creating a physical volume on a disk can it used in a VG.?

Regards,
Rahul

Re: Disk replacement

johnsonpk — Sun, 21 Feb 2010 08:11:46 GMT

>>I did not use pvcreate -B (this could be 3rd step).
You should not use the pvcreate comand as the pv is already recorded in lvmtab.(command will fail with error"physical volume is already recorded in lVMTAB)

vgcfgrestrore will take care of creating LVm structure on the replaced disk

>>please let me know that without creating a physical volume on a disk can it used in a VG.

please not that ,At some point of time you did a pvcreate on the same disk device file for adding that to the VG and as a result, that disk is marked as pv and became part of lvmtab.And now your system knew that there was a pv on the replaced disk's device path and for some reason it was not available for some time.

Re: Disk replacement

Johnson Punniyalingam — Sun, 21 Feb 2010 08:19:51 GMT

>>>I did not use pvcreate -B (this could be 3rd step).please let me know that without creating a physical volume on a disk can it used in a VG.?<<<

Yes, It can be used in "vg" .. but it will not boot, that's the purpose using (pvcreate -B /dev/rdsk/cxtxdx) -B option will Make a physical volume bootable (i.e. a system disk).

man pvcreate

pvcreate recognizes the following options:

-B Make a physical volume bootable (i.e. a system
disk).

HTH,
Johnson

Re: Disk replacement

Rkumar — Sun, 21 Feb 2010 09:32:59 GMT

thanks johnsonpk but then how can i make that alternate disk bootable as to make the disk bootable i need to run this command pvcreate -B but this will give error that pv is already recorded in lvmtab. Please suggest.

Regards,
Rahul

Re: Disk replacement

Rkumar — Sun, 21 Feb 2010 09:37:30 GMT

Thanks Dear experts at last i got resolved my query. Points have been awarded to all experts.

Regards,
Rahul

Re: Disk replacement

johnsonpk — Sun, 21 Feb 2010 12:03:23 GMT

>>how can i make that alternate disk bootable as to make the disk bootable i need to run this command pvcreate -B but this will give error that pv is already recorded in lvmtab. Please suggest.

pvcreate with -B option creates an area on the disk for a LIF volume, boot utilities, and a BDRA (Boot Data Reserved Area).

and mkboot is for placing boot utilities in the boot area:(BDRA)

Here vgcfgrestore will take care of restoring LVM structure includin BDRA,and there for you only need to copy the bootprogram into it by mkboot command.

However you may consider doing mkboot and lvlnboot -R before executing the shutdown command.( i guess shutdown is for test booting the server from replaced disk )

Re: Disk replacement

Rkumar — Sun, 21 Feb 2010 12:14:10 GMT

Tahnks Johnsonpk,

This is what I m waiting for. Points have been awarded for this.

Regards,
Rahul

Re: Disk replacement

kashyapi — Mon, 22 Feb 2010 13:35:29 GMT

Hi Rkumar,

I am confused about rebooting the system as you mentioned the steps.Did you check whether you are able to boot from Alternate disk which you have replaced.Actualy reboot is not required.

Secondly, can you pls check the output of lvlnboot -v and check whether boot,root,swap and dump is configured.You may not see boot lvol configured.In that case you may have to run lvlnboot -b /dev/vg00/lvol1