How to replace failing root mirror disk?

[Byron Myers]

L2000 with failed mirrored vg00 disk.
The old method was to go to single user mode to replace a bootable disk. With the L's, can this be done without having to shutdown the system (i.e. online)?

[Sanjay_6 · Accepted solution]

Hi Byron,

This link should help you,

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=55c2915c0f99cbb5e0/screen=ckiDisplayDocument?docId=200000058036738

Hope this helps.

Regds

[Craig Rants]

This doc should help out.

GL,
C

[James R. Ferguson]

Hi Byron:

If the disk in question is hot-swappable then you can do the following:

> Hot swap the affected disk.
> 'lvreduce -m 0' each mirrored LV
> 'vgreduce' the replaced disk from the VG
> recreate the mirrored disk beginning with 'pvcreate -B' since this is your root disk.

Regards!

...JRF...

[Krishna Prasad]

All please tell me if I am wrong here but wouldn't this work.

Staying on-line

1. replace bad-disk
2. vgcfgrestore /dev/vg00 /dev/dsk/c#t#d#
3. vgchange -a y /dev/vg00
4. vgsync /dev/vg00 /dev/dsk/c#t#d#
5. mkboot /dev/rdsk/c#t#d#
6. mkboot -a "hpux (0;)/stand/vmunix" /dev/dsk/c#t#d#

[Byron Myers]

Okay,
Craig's reference says I have to reboot to single user mode - my question is do I actually have to do this with a hot-swappable disk on HP-UX 11.0?
Jame's method contradicts Craig's doc - about
lvreducing the mirrors and vgreducing the failed disk.
Sanjay's doc looks like what I am looking for, but the last step here says to reboot.

Do I actually need to reboot this system after replacing the hot-swappable disk and doing the steps in Sanjay's doc?

[Helen French]

Hi Byron,

Some other thoughts ...

1)Check out 'lvlnboot -v' and make sure that both disks are configured as root hard disks.

2) As L2000 comes with hot-swap disks, you can replace the disk online.

3)It is recommended to put 'hpux -lq' when doing mkboot string config.

HTH,
Shiju

[James R. Ferguson]

Hi Byron, et al:

I taken a very conservative approach. There are potential issues with doing a 'vgcfgrestore' with mirrored disks in 11.0 depending on patch levels. The method I've cited is one I've used before. Have a look at Technical Knowledge Base document #S3100004601.

Regards!

...JRF...

[Sanjay_6]

Hi Byron,

If the root disk that you want to replace is a hot-swap, i don't see any reason why you must reboot the system. Make sure all the lv's are mirrored. Take a os backup if you can. Remove the faulty disk. Wait for a few minutes, put the new disk in. Do a vgcfgrestore, do a vgchange for vg00, do a mkboot to put the lif info on new disk and put the boot string using mkboot -a, then do a vgsync to rebuild the mirror.

however it is always safe to boot using the mirror if the primary is failing, replace the disk, rebuild the mirror, reboot using the primary. I have never tries to do the hot-swap primary root disk replacement myself without rebooting the server.

Hope this helps.

regds

[Craig Rants]

Byron,
What you do is up to you. I just can tell you from my experience (with "hot plugable drives") that this process works. There may be others that work better or differently, I just know that I have used this and it does the job for me.

GL,
C

[Byron Myers]

Thanks to all for the responses. I replaced the disk using the online method (Sanjay's and Ron's responses). This method worked fine. I did not have to reboot the system.