On Thursday May 27, tharvey@xxxxxxxxxxxxxxxxxx wrote: > > It looks like I need to do an 'mdadm --assemble' to assemble the > previously created array into an active array. But I'm not clear how to > examine the /dev/md0 device to see what partitions are available (fdisk > didn't work in a test... I guess its not compatible with /dev/md0). > /dev/md0 will not have any partitions. It will just have a filesystem. You could try 'fsck -n /dev/md0' to see if the filesystem is recognised. > > > > Issue #1 Can be assured (AFAIK) by just attaching one disk less. Then > the > > array will be in degraded mode and cannot / will not attempt a resync. > > In addition, this will enable you to choose another set of disks, > should > > the > > outlook on the first three be less than favourable... > > > > Does disallowing the raid to start any reconstruction mean that the > array is not 'started' and that I cannot mount the filesystem? I guess > I'm not clear if there is a difference between the array being 'started' > and 'allowing reconstruction'. Is leaving a disk out of the RAID5 array > the only way to force this to occur? I noticed mdadm has a --readonly > option but I'm not sure if it affects the assemble mode. "starting" an array is like mounting a filesystem. It makes it accessible. There is no simple way to start an array but not let it reconstruct. '--readonly' doesn't do this (though it probably should). Leaving one drive out disables reconstruction simply by making it impossible. > > > Issue #2 Should be assured by mounting read-only, without prior fsck. > > > > Sounds like a safe bet to mount the partition read-only. How can I > examine /dev/md0 to see what partitions are available? I'm fairly > certain XFS is used. The RAID HOWTO doesn't seem to go into detail > regarding how to examine filesystems on an array. There are no partition tables. Just a filesystem. Does xfs have a check-and-repair tool? Try that. 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
