[dm-devel] Status of resizing/growing dm-multipath devices on the fly

[Domenico Viggiani]

* Pasi Kärkkäinen wrote:
> 
> Is it possible to resize (grow) dm-multipath devices on the 
> fly nowadays?
> 
> I googled and found some discussions about the subject, but 
> the conclusion seemed to be it's not possible.. that was a 
> while ago, so I was wondering if this has been fixed/implemented..
> 
> Using LVM and adding another new LUN/PV is not an option 
> always.. it's a lot easier to manage the whole thing if it's 
> possible to resize/grow existing LUNs on the fly.

Nowadays all disk-arrays make online LUN extension a breeze but
unfortunately it seems that dm-multipath is still not able to see new size
without downtime:
 http://www.redhat.com/archives/dm-devel/2007-August/msg00205.html
Look also at this recent thread on RHEL5 mailing-list where you can find
also a post from a Red Hat representative:
 http://www.redhat.com/archives/rhelv5-list/2008-July/msg00267.html

Sure, you can just add a new LUN, pvcreate and vgextend but it is not a
viable solution because it causes LUN proliferation.

Sincerely, I'm still subscribed to this mailing-list only to see if someone
solve this SHAME!
It's a feature that Linux really needs.

Hope someone pick this cry of pain!

--
Domenico Viggiani