Extending a mirrored filesystem

[Stephen Young_1]

Can someone tell me the syntax for extending
a mirrored lv when there are more than two pv's
in the volume group.

Cheers in advance

[James R. Ferguson]

Hi Stephen:

To mirror onto a specific disk use this syntax:

# lvextend -m 1 /dev/vgXX/lvolX /dev/dsk/cXtYdZ

...JRF...

[Vincent Stedema]

Hi Stephen,

lvextend the primary lvol to the disk you want the newly allocated PE's to reside on. Use lvdisplay to determine on which disk in your vg the mirrored PE's are located and then use pvmove to move the mirrored data to the disk you want to use as the secondary disk.

Hope this helps.

Vincent

[Vincenzo Restuccia]

#lvextend -m 1 /dev/vg00/lvolx /dev/dsk/cxtxd0
and see http://docs.hp.com/hpux/onlinedocs/B2355-90672/B2355-90672.html

[Carsten Krege · Accepted solution]

James gave you the syntax of how to create a mirror copy of an unmirrored lvol.

The following gives you the syntax of increasing the size of an mirrored lvol.

lvextend -l /dev/vgXX/lovlX /dev/dsk/ /dev/dsk/

This will extend the size of the lvol to newsize (numbers of physical extents), taking the extents from disk1 and disk2. With the allocation policy set to "strict" (default) the two mirror copies of the disk will always be on different disks.

You might be interested in using physical volume groups. A full descriptiuon of this feature, together with examples, is in the manpage lvmpvg(4). Once setup, it will always take care that the allocation of extents is done properly.

Carsten