How do you expand a RAID5 Array?

Lennart Sorensen lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org
Tue Aug 11 14:04:45 UTC 2009


On Mon, Aug 10, 2009 at 10:00:10AM -0400, William O'Higgins Witteman wrote:
> I have a server with three drives in a RAID5 configuration.  I have
> three more drives which I would like to add.  Do I just plug them in, or
> do I need to plug them in a reboot, or will it require a reinstall of
> the OS?

Depends on the controller.

AHCI controllers should support hot plug, although I have seen one case
where a hotplug caused another drive on the controller to momentarily
disappear, which didn't please the raid at all.  I suppose having hot
swap cages makes it more reliable.

Other than that, you partition the drives, then mdadm can be used to add
drives to expand an existing raid (at least with recent kernel versions
and mdadm versions).

With hardware raid, it depends what the raid controller and its control
software is capable of.  Some can do raid resizes.  Some can't.

-- 
Len Sorensen
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists





More information about the Legacy mailing list