Re: raid5/lvm setup questions

On Saturday August 5, shane@cm.nu wrote:

On Sat, Aug 05, 2006 at 06:31:37PM +0100, David Greaves wrote:

quoted

quoted

Say going from 300gbx4 to 500gbx4.  Can one replace them
one at a time, going through fail/rebuild as appropriate
and then expand the array into the unused space

Yes.

I didn't see anything in the mdadm manual on this.  Would
one just do a --grow /dev/md0 once the disks were changed
out?  It looks like --grow is used to change the number of
devices in the array but not the device size itself.

It does both (and more).

 mdadm --grow /dev/md0 --raid-disk=5
changes the number of drives to 5.

 mdadm --grow /dev/md0 --size=max

changes the used-size of each drive to the maximum available.

 mdadm --grow /dev/md0 --bitmap=internal
adds an internal write-intent bitmap

 mdadm --grow /dev/md0 --chunksize=128
might change the chunksize to 128k.. but doesn't yet.  
Maybe one day :-)

NeilBrown