Replacing fault disk - help required please

[seanharrodine]

Hi there,
(HP9000 and Jamaica hotswap disk array)

We have a problem with a hotswap 4.5GB Seagate disk and need to swap it out this evening.
Replacement has arrived so i am looking for a little advice as to the procedure please.

The disk shows as still being ok and CLAIMED in Ioscan.

The faulty disk (/dev/dsk/c4t5d0) is in volume group vg02.

Volume group vg02 only has 1 logical volume (/dev/vg02/u01_oradata)

Volume group vg02 has 2 physical volmes (c4t5d0 and c5t5d0)

VG02 also has 2 physical volume groups (pvg02 and pvg02m) and just mirror each other.

The disks contain Oracle data files and we would prefer not to bring Oracle down if that is possible.

Could someone confirm please the procedure we need to go through to pull the disk out, replace it with our new disk and sync it please.

Many thanks,
Sean

[James R. Ferguson]

Hi Sean:

The best guide to disk failure/replacement woes is this:

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

Regards!

...JRF...

[Pete Randall]

I believe the required steps should be covered in this document:

http://www.docs.hp.com/en/5971-2383/5971-2383.pdf


Pete

[IT_2007 · Accepted solution]

If you want to replace mirror disk and which is not completely dead yet then don't do simply replacement. Do the following.

1. Break mirror for all logical volumes from the bad disk using
lvreduce -m 0 /dev/vg02/lvol1
2. Once you successfully reduced logical volumes then you need to reduce from volume group.

vgreduce /dev/vg02
3. Confirm that vgdisplay -v vg02 doesn't show bad disk at all then simply remove it and replace with new disk.

4. ioscan -fn will still show same device file.

pvcreate /dev/rdsk/cXXtYYdZZ
vgextend /dev/vg02 /dev/dsk/cXXtYYdZZ
then mirror all logical volumes.

This procedure would be safest way to do it online.

[Pete Randall]

Sean,

Please ignore my response, I managed to cut and paste the wrong URL. James has the correct one for you.


Pete

[seanharrodine]

thanks for the replies.I have a vague recollection of running vgsync / vgchange previously when replacing a disk for some reason or other, but presumably this was due to a different type of failure ?tiaSean

[IT_2007]

thanks for the replies.I have a vague recollection of running vgsync / vgchange previously when replacing a disk for some reason or other, but presumably this was due to a different type of failure ?tiaSean
==============================

vgsync you can use if disk was dead and then you restore configuration using vgcfgrestore.

vgcfgrestore -n /dev/vg02
vgsync /dev/vg02

Those two commands will be doing together only if disk is completely dead otherwise you have to reduce logical volumes and then volume group from the bad disk.

[seanharrodine]

thanks again for the reply.A colleague of mine has volunteered to save me the trip onsite to replace the disk so i will let you know tomorrow the outcome.Sean

[seanharrodine]

All sorted guys - many thanks for the input !Everything went to plan.rgds,Sean