AIX

Thanks for the reply. Can I conclude that if to mirrorvg to one disk I do not require perform extendvg unless more than 1 disk ?

No, quite the opposite: you can use the "mirrorvg" command only on disks you added with "extendvg" before.

I hope this helps.

bakunin

There is no need to mirror, sync then un-mirror. You can:-

Code:

extendvg appvg hdisk3 hdisk4
migratepv hdisk1 hdisk3
migratepv hdisk2 hdisk4
reducevg appvg hdisk1 hdisk2

The migration phases will take a long time (same as a mirror and sync) but it's less prone to error. I'm assuming that the target disks are at least the same size as the source.

You may want to consider stopping the database and HA too, but test this elsewhere and see if you need to take services down. It might be fine as the OS maintains access to the LV even with updates happening. I'm just very cautious.

I hope that this helps.


Robin
Liverpool/Blackburn
UK

Here the steps to perform HACMP Mirrorring

Code:

To mirror in hacmp
------------------
smitty hacmp

system management (c-spoc)

 HACMP Logical Volume Management

   Shared Volume Groups

     Mirror a Shared Volume Group

	 Select a volume_group to mirror

** select disks to mirror

After this need to issue command to sync

System Management (C-SPOC)
	HACMP Logical Volume Management
		 Synchronize Shared LVM Mirrors
			Synchronize by Volume Group


Do take note, only select and run those vg that in the active node.

You can copy out the script (F6)

This will work only with ECC (enhanced concurrent capable) VGs. Shared VGs need RW-access on one (the active) node and RO-access on all the others. You can have that only with SCSI-3 (SCSI-2 would have disk reservations) and fast disk takeover, which means ECC. There are some storage systems, though, (for instance the EMC CLARiiON), which will not allow concurrent access to mirrors.

In such cases you have to mirror the volume group on the active node with classic AIX means, switch the primary mirror over to the other node during a downtime, do a "learning import" (importvg -L) and then restart the cluster.

I hope this helps.

bakunin