[CentOS] LVM - pvmove and multiple servers

Sat Jan 10 19:50:27 UTC 2015
John R Pierce <pierce at hogranch.com>

On 1/10/2015 5:13 AM, Daniel Hoffman wrote:
> Looking for some guidance/experience with LVM and pvmove.
> I have a LUN/PV being presented from a iscsi SAN. The LUN/PV is presented
> to 5 servers as a shared VG they all have LV's they use for data, they are
> all connected via iSCSI.
> As the SAN I am using is being replaced I need to move onto a new unit.
> My migration strategy at this time is to
> 1. Present a new LUN from the new SAN to all machines.
> 2. Make a PV with the new LUN.
> 3. Add it to the existing VG.
> 4. Use pvmove to move all the data from one PV to another.
> 5. Once the old LUN is empty, complete a pvresize to remove the old LUN.
> This all seems sound but looking for advice, specifically around the fact
> that the VG/PV data is being used by a number of machines/servers and the
> LV's are active on a number of different nodes.
> All the documentation/examples I can find assume a disk in a server, not a
> LUN on a SAN being shared by a number of servers.

only way I'd do that would be to shutdown the other 4 servers, redo the 
LVM, then bring the other 4 servers back up so they can discover the new 
LV/PV structures.

john r pierce                                      37N 122W
somewhere on the middle of the left coast