Hello,

I have a 2 node Red Hat 7 cluster that uses two shared iSCSI LUNs in an LVM mirror for the shared application mount point.

I had our storage admins expand the LUNs from 1.5TB to 3TB. I am now trying to determine how to safe expand the volume group and the logical volume.

I think I know the procedure, but I am not 100% sure on it:

- break LVM mirror
-format the unallocated space into a new logical volumes
- add new logical volumes to VG Group
- expand vg
- expand lvm

Is that the correct procedure? And if so, how do I safely break the mirror?

Thanks!

There appears to be some terminology mismatch in what you wrote.

LVM = Logical Volume Manager
PV = Physical Volume
LV = Logical Volume
VG = Volume Group

What you say about LVM is actually an LV based on what you wrote.
What you say about "logical volume" is actually PVs based on what you wrote.

I'm not sure you have to break the mirror to extend a mirrored LV but the man page isn't clear on this point and does talk about unintentionally using extents so it may be a good idea.

The command both to create and remove a mirror is lvconvert.

Hello,

Sorry for the terminology mismatches. Yes you are correct. I am trying to expand a mirrored LV group.

Hello, here is some further clarification.

I have a 2 node ha cluster.. I created VG "vg_cluster" which contains two iSCSi LUNS, using disks: /dev/mapper/mpatha1 and /dev/mapper/mpathb1 . I then created a mirrored LV called "lv_cluster".

Both iSCSI LUNs were 1.5TB, but I had to expand them to 3.0TB. Both nodes see the size increase after rescanning the bus.

I am now trying to figure out how to grow the LV to 3.0TB...

Normally you would just add a new partition using the free space, and add that partition to the VG.. But I am not sure if that would work in this situation.

Any help is greatly appreciated. Thanks!