On Fri, 2 Sep 2011 10:12:32 +0100 Michael Busby <michael.a.busby@xxxxxxxxx> wrote: > Thanks Neil > > Is there anyway back from raid0 to raid4 as i know once at raid0 i > will no longer be able to add any disks, in theory i could change > echo raid0 > /sys/block/md0/md/level,but this would require adding a > missing disk to the raid4 at the same time, not sure how easy that > would be todo > Yes, you can switch from RAID0 to RAID4 in much the same way as you switch from RAID4 to RAID0. You can then freeze/add-disk/change-size/unfreeze/wait/switch-back-to-RAID0 to add more devices. mdadm-3.2.2 should be able to do all this for you. i.e. you ask it to --grow a RAID and --add some disks at the same time, and it will do all the required magic. This hasn't been tested extensively, but should work in simple cases. Of course the more devices you have in a RAID0, the less reliability you have - but e.g. as a cache for a tape backup system a large RAID0 is fine. NeilBrown -- 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
