mirror striped lvol

[Jiri D]

Hi,

I have a striped lvol on 3 pv. I need move this lvol on another 3 disk with the same size. Can I mirror this lvol via lvextend -m 1 new_disks. When mirror will be competed - lvreduce -m 0 old_disks. Will I have a striped lvol?

Jirid

[Elmar P. Kolkman]

This should work, yes.

You can check with lvdisplay -v after adding the mirroring. LE's should be linked to PE's the same way on the mirror as on the original.

[Bernhard Mueller]

Jirid,

you cannot LVM mirror lvols which are LVM striped - using -i -I options in lvcreate. You can only mirror lvols that use "distributed extents" (lvcreate -D y).

But you can use the pvmove command to move extents of an lvol from one disk to another in the same vg.

Regards,
Bernhard

[Jeff Schussele]

Hi Jirid,

Sorry, no you cannot mirror an LV with "normal" striping that was created with the -i & -I parms of the lvcreate cpmmand.

The only striping that can be mirrored are extent-based stripes created by the -D parm of vgcreate. This is normally an ineffective method of striping as the smallest stripe size is 1 MB.

Rgds,
Jeff

[Jeff Schussele]

Sorry - the distributed allocation parm, -D, is an lvcreate parm not a vgcreate switch.

Rgds,
Jeff