On Tuesday May 16, Dexter.Filmore@xxxxxx wrote: > > Right now all that's in mdadm.conf is: > > DEVICE /dev/sd[abcd]1 > ARRAY /dev/md0 devices=/dev/sda1,/dev/sdb1,/dev/sdc1,/dev/sdd1 > MAILADDR root@localhost > > Something important missing..? If these are the only SCSI drives (or USB or anything else that looks like a SCSI drive) that you have or will ever have, then it is probably safe. If you plug another device in and reboot, that other device could conceivably become sda, and your current devices will be b,c,d,e. If this happened, then mdadm could have trouble assembly your array. At best it would be degraded as sde would not get included. So in the very simple one-array situation, this is probably safe. But it doesn't generalise. If you have two array of distinct devices, then something like ARRAY /dev/md0 devices=/dev/sda1,/dev/sdb1,/dev/sdc1,/dev/sdd1 ARRAY /dev/md1 devices=/dev/sde1,/dev/sdf1,/dev/sdg1,/dev/sdh1 is not safe. If /dev/sda1 fails, you pull it out and reboot, then md1 won't be assembled properly as everything will get renamed. In general it is safer to use UUIDs DEVICE /dev/sd[a-z][0-9] ARRAY /dev/md0 uuid=whatever ARRAY /dev/md1 uuid=whatever:else Hope that makes it reasonably clear. 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
