Hi Neil, On Fri, Sep 13, 2013 at 10:43 PM, NeilBrown <neilb@xxxxxxx> wrote: > On Fri, 13 Sep 2013 15:22:20 +0200 Francis Moreau <francis.moro@xxxxxxxxx> > wrote: > >> Hi Neil, >> >> I'm probably doing something wrong since it's a pretty critical bug >> but can't see what. >> >> I'm creating a RAID1 array with 1.2 metadata. After that I stop the >> array, and restart the array with only one disk. I write random data >> on the array and then stop it again: >> >> # mkfs.ext4 /dev/md125 >> # mdadm --stop /dev/md125 >> # mdadm -IRs /dev/loop0 >> # mount /dev/md125 /mnt/ >> # date >/mnt/foo >> # umount /mnt >> # mdadm --stop /dev/md125 >> >> Finally I restart the array with the 2 disks (one disk is outdated) >> and mdadm happily activates the array without error. Note that I add >> the outdated disk first in that case: >> >> # mdadm -IRs /dev/loop1 >> mdadm: /dev/loop1 attached to /dev/md/array1, which has been started. >> # mdadm -IRs /dev/loop0 >> mdadm: /dev/loop0 attached to /dev/md/array1 which is already active. > > That's a worry. I'm not sure how to fix it. > > I would probably suggest you don't use "-IR" to add devices. That would make > it a lot less likely to happen. > Well I'm not sure how I should start an array... For example doing: # mdadm -I /dev/loop0 # mdadm -I /dev/loop1 # mdadm -R /dev/md125 works for array using metadata 1.2 but doesn't if the array is using DDF (mdmon not started). To workaround this issue you suggested to use -IRs: # mdadm -IRs /dev/loop0 # mdadm -IRs /dev/loop1 but now mdadm can't detect outdated disk anymore. Could you suggest something to start an array which would work in all cases (ddf or 1.2, add non-fresh disk...) ? > >> # cat /proc/mdstat >> Personalities : [raid1] >> md125 : active raid1 loop0[0] loop1[1] >> 117056 blocks super 1.2 [2/2] [UU] >> # mount /dev/md125 /mnt >> # ls /mnt/ >> [ 457.321771] EXT4-fs error (device md125): ext4_lookup:1047: inode >> #2: comm ls: deleted inode referenced: 12 >> ls: cannot access /mnt/1: Input/output error >> >> If I add the outdated disk last I got this: >> # mdadm -IRs /dev/loop0 >> mdadm: /dev/loop0 attached to /dev/md/array1, which has been started. >> # mdadm -IRs /dev/loop1 >> mdadm: can only add /dev/loop1 to /dev/md/array1 as a spare, and >> force-spare is not set. >> mdadm: failed to add /dev/loop1 to existing array /dev/md/array1: >> Invalid argument. >> >> which didn't tell me the reason why loop1 must be a spare. > > It must be a spare because it is out of date. > Yes but I think mdadm should tell the reason, no ? Thanks -- Francis -- 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
