On Thursday December 4, chris@xxxxxxxxxxxx wrote: > Chris Webb <chris@xxxxxxxxxxxx> writes: > > [Re: mdadm --stop being potentially asynchronous] > > The reason for the question is that I'm seeing occasional cases of arrays which > > won't reassemble following such an operation. dmesg alleges there is an invalid > > superblock for all of the six slots which were originally part of the array. > > I tracked this one down to my scripts, which were failing to adjust the > available space on the rdevs in a particularly rare case. However, I'm still > wondering about the best way to do a fail/remove combination, given > that fail appears to be asynchronous. The shell fragment I give below seems > way over the top, but I can't see any simpler route.... Yes, --fail is asynchronous and I suspect it will remain that way. It is up to the raid array to decide when to let go of the device and it might never do say: if you fail the last working drive on a raid1, you still cannot remove it. > > > I notice that some mdadm operations appear to be asynchronous. For instance, > > > > mdadm --fail /dev/md/shelf.51000 /dev/mapper/slot.51000.1 > > mdadm --remove /dev/md/shelf.51000 /dev/mapper/slot.51000.1 > > > > will always fail at the --remove stage with > > > > mdadm: hot remove failed for /dev/mapper/slot.51000.1: Device or resource busy > > > > whereas adding a short sleep in between will make it successful. > > > > Is there a 'standard' way to wait for this operation to complete or to > > perform both steps in one go, other than something horrible like: > > > > mdadm --fail /dev/md/shelf.51000 /dev/mapper/slot.51000.1 > > MD=$((`stat -c '%#T' -L /dev/md/shelf.51000`)) > > MAJOR=$((`stat -c '%#t' -L /dev/mapper/slot.51000.1`)) > > MINOR=$((`stat -c '%#T' -L /dev/mapper/slot.51000.1`)) > > for RD in /sys/block/md$MD/md/rd*; do > > [ -f $RD/block/dev ] || continue > > [ "`<$RD/block/dev`" = "$MAJOR:$MINOR" ] || continue > > while [ "< $RD/state" != "faulty ]; do sleep 0.1; done > > done > > mdadm --remove /dev/md/shelf.51000 /dev/mapper/slot.51000.1 I suspect until mdadm --remove /dev/md/shelf.51000 /dev/mapper/slot.51000.1 do sleep 0.1 done might be slightly simpler. NeilBrown > > Cheers, > > Chris. > -- > 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 -- 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
