Le Mon, 16 Feb 2009 13:34:50 +0100, Rémi PALANCHER <remi.palancher@xxxxxxxx> a écrit : > Hi there, > > I've been a happy and successful mdadm user for a while now, but > unfortunately, I met a problem recently. > > I use mdadm to manage a RAID5 array with 5 disks and 1 spare. The > devices in the array are sda5, sdb1, sdc1, sdd1, sde1 and sdf1. Before > things start to go wrong, sdb1 device was the spare and the other > devices were active in the array. Here is this configuration as shown > by the logs: > > [85054.372171] RAID5 conf printout: > [85054.372175] --- rd:5 wd:4 > [85054.372177] disk 0, o:1, dev:sdc1 > [85054.372179] disk 1, o:1, dev:sde1 > [85054.372181] disk 2, o:1, dev:sda5 > [85054.372183] disk 3, o:1, dev:sdd1 > [85054.372185] disk 4, o:0, dev:sdf1 > > Last thursday, a problem occured on sdf1 and mdadm started recovering > the array with sdb1 as expected. But sdb1 have had a problem too > during the recovery process, but the array continued to run properly > with the last good 4 devices. I can attach logs if needed. Actually, > sdb1 was defective, and I removed it physically from the server. > > But here is the output when I try to reassemble the array with the > remaining devices: > # mdadm --assemble /dev/md0 --force \ > --verbose /dev/sda5 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 > mdadm: looking for devices for /dev/md0 > mdadm: /dev/sda5 is identified as a member of /dev/md0, slot 5. > mdadm: /dev/sdb1 is identified as a member of /dev/md0, slot 0. > mdadm: /dev/sdc1 is identified as a member of /dev/md0, slot 3. > mdadm: /dev/sdd1 is identified as a member of /dev/md0, slot 1. > mdadm: /dev/sde1 is identified as a member of /dev/md0, slot -1. > mdadm: added /dev/sdd1 to /dev/md0 as 1 > mdadm: no uptodate device for slot 2 of /dev/md0 > mdadm: added /dev/sdc1 to /dev/md0 as 3 > mdadm: no uptodate device for slot 4 of /dev/md0 > mdadm: added /dev/sda5 to /dev/md0 as 5 > mdadm: added /dev/sde1 to /dev/md0 as -1 > mdadm: added /dev/sdb1 to /dev/md0 as 0 > mdadm: /dev/md0 assembled from 3 drives and 2 spares - not enough to > start the array. > > I can understand why sde1 (previously sdf1) cannot take an active > slot, but why does sda5 wanna take slot5 instead of slot2, as it was > previously? > > Is there any way to force it? FYI, I finally found a (ugly) way to force sda5 to take slot2 by doing this: # mdadm --run /dev/md0 (An error was shown here, but devices appeared in /sys regardless) # cat /sys/block/md0/md/dev-sda5/slot 5 # echo 2 > /sys/block/md0/md/dev-sda5/slot # mount -o ro /dev/md0 It's quite ugly and probably not the best way to do it, but fortunately it worked! -- Rémi PALANCHER Ingénieur associé Administrateur systèmes et réseaux Grid'5000 INRIA Saclay Bâtiment H tel : 01 74 85 42 45 Bureau : 015 mob : 06 31 99 95 17 -- 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
