On Fri, 26 Nov 2010 09:07:38 +0100 Adam Kwolek <adam.kwolek@xxxxxxxxx> wrote: > Spares are used by Online Capacity Expansion to expand array. > To run expansion on raid0, spares have to be added to raid0 volume also. > Raid0 cannot have spares (no mdmon runs for raid0 array). > To do this, takeover to raid5 (and back) is used. mdmon runs temporary for raid5 and spare drives can be added to container. > > Signed-off-by: Adam Kwolek <adam.kwolek@xxxxxxxxx> I don't like this patch at all. There is a lot of code in here that is very specific to IMSM, that has been placed directly in Manage.c. That is bad. I gather you want to support mdadm /dev/md/imsm --add /dev/newdisk on a RAID0 and have it convert to RAID5, do the restripe, and convert back. The IMSM specific code goes through a container and converts every member array to raid5. The mdadm /dev/md/imsm --add /dev/newdisk should just add the device to the container as a spare. This might require updating the IMSM metadata in some way, but doesn't require changing anything to RAID5 and back. Then when you do mdadm -G /dev/imsm --raid-disks=4 it will work with the imsm code to update every member array and add parts of the newdisk to each array. The conversion to RAID5 needs to happen in Grow_reshape when raid-disks is changed on a RAID0. It needs to happen while the array is frozen. Not in Manage.c NeilBrown > --- > > Manage.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 153 insertions(+), 1 deletions(-) > -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
