LVM "pvmove question"

[NIGEL WHITE_2]

Hello,

We are just about to migrate our volumes from EVA SAN Luns to Netapp SAN Luns and was wondering if LVM on HPUX works the same way as Redhat 4??

Example:

1xVolume Group containg 1 EVA lun.
I add a Netapp lun to the VolumeGroup and PVmove the extents from one lun to the other. This has worked great within our Redhat server but I need to know if HP-UX works the same? Doe's HP LVM move or copy the extents in case of failure during the migration????

Anyone else done this type of migration using pvmove on HP-UX 11 ?????

Regards
Nigel

[Patrick Wallek]

pvmove actually uses mirroring to do its work.

In a nutshell, it will extend the mirror to the new LUN and when that finishes reduce the mirror from the old LUN.

If something interrupts the operation, you can have issues.

That being said, I have used pvmove to move data around numerous times without any problems whatsoever.

[NIGEL WHITE_2]

Thanks Patrick.

yea, just been advised that our second Redhat server has died while trying to pvmove vg00 extents that contain the OS.

Maybe pvmove is better for none OS extents, or though it should not matter if it uses mirroring???

Tar anyway.

Nigel

[Ganesan R]

Hi,

pvmove will do but it is atomic operation. It can be easily interupted and will lead into weired state.

Why can't add the new LUN into the VG and mirror all lv's to the new LUN and break the mirror from old one. Later on you can remove the old LUN from the VG.

[NIGEL WHITE_2]

From what Patrick advises, we are doing that anyway????

I have succesfully pvmoved a volume group containing /opt/oracle without disruption, but when we tried it on a volume group containg Redhat 4 OS, it died on us at 80% ???

Its a test server anyway, so no real harm has been done.

just wondering why it should fail on volume containg an OS ???

R.
Nigel