Possible to Non-Distructively Migrate an LVOL from one VG to Another?

[Alzhy]

Can't recall if I asked this question before but with VxVM (Veritas), I can non-distructively move LVOLS(volume) and their PV's (dm disks) to another VG (diskgroup).

Is this possible under LVM ?

[Alzhy]

Also, when I lvreduce an LVOL and vgreduce a PV from a VG, does the PV actually get blanked/nulled out? In VxVM - it does not so one can migrate volumes (LVOLs) from one Diskgroup (VG) to another.. as long as a vxmake file (from vxprint) is done..

[RAC_1]

Not possible with LVM.

Create a new volume under the VG you want.
copy/mv/backup-restore data on new lvol.

Anil

[Geoff Wild]

nope - not with lvm - you will have to create a new vg/lvol, then copy data - say with vxdump:

vxdump -0 -f - -s 1000000 -b 16 /oldmount | (cd /newmount ; vxrestore rf -)


Rgds...Geoff

[Alzhy]

Take note... I am sure how my LVOLS are structured on the PV's.

The plan is with LVM Mirrors, we can split mirrors and move the component PV's of those mirror/split LVOLs out of the VG and create a new VG on its own -- possibly on a different host as the PV's (Luns) are multi-hosted (visible on other hosts).

[Pete Randall]

There is the pvmove command but that's not really what you're looking for - it's only within a VG.


Pete

[Ashwani Kashyap]

No not possible to in LVM . In LVM you cannot move LV's acroos VG's .

Only way to do is make another VG/LV and copy the data across .

YOu can only move the LV onto a different disk/lun in the same VG .

[Alzhy]

Apparently I asked this some time ago and Yes indeed it is possible:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=75321

As I have tested it on LVM on Linux as well...

[Geoff Wild]

Before doing that - I would make sure I had a good backup.....just in case....

Rgds...Geoff

[Sridhar Bhaskarla]

Nelson,

You have to remember couple of things.

1. You can *attempt* to move by moving the whole PV. Not a single LV or if the PV has multiple LVs on them.

2. If the extent size of the other VG is different from the original VG, it may not work.

3. If you lose any data and if you place a call with HP, then they will simply say they won't support it.

With all the above, you can generally and officially say 'it doesn't work'.

But you can still try with the background that it may not work always. I believe in trying.

-Sri

[Scott Van Kalken]

vxdump 0f - /usr | (cd /mnt; vxrestore xf -)

...straight from the restore man page.

I quite like this method.