Mirroring for backup Restore of application software

[Atul Goel]

Thanks Eric and John for such a detailed information

One more question
Can i use lvreduce commands for my rollback ?
Once i remove mirroring using lvreduce do the reduced disk still have the data? Can the data on reduced disk be availabel for use?

[Eric SAUBIGNAC · Accepted solution]

Not sure to clearly understand your question.

Once mirror has been delete with "lvreduce -m 0", data on the old mirror is still available, but LVM structure has been modified, so that it doesn't keep track of the mirrored part. So it will be difficult to access data on the removed mirror part. Not impossible, but difficult. If you want to keep in a corner the mirror disk I would do this way (short description as I must leave ;-) :

- deactivate VG
- remove the disk(s) that support mirrored LV parts and keep in a safe place.
- ioscan --> mirror disk in "NO_HW" state
- reactivate the vg with quorum option "-q n"
- suppress mirroring with option "-m 0 -k - suppress removed disk with option "-f" of vgreduce
- de-activate then re-activate the VG

The disk you have extracted is now available for use in an other system. You will have some manipulations to do, but it will be OK.

Regards

Eric

[john123]

If u just lvreduce i think it will not work.... But another idea would be to pull the mirror disk out, then do an lvreduce -f. it should work.. although I wont recommend you to do that.

regards
John

[James R. Ferguson]

Atul:

You don't state what HP-UX release you are running. If you are on 11.23 or 11.31 you should look at Dynamic Root Disk (DRD):

http://h20392.www2.hp.com/portal/swdepot/displayProductInfo.do?productNumber=DynRootDisk

Regards!

...JRF...

[Atul Goel]

Can i use that disk for rollback of the system. what manipulations do we need to perform?? Can you kindly detail them??

[Atul Goel]

Thanks all of you for wonderful answers