On Sun, 1 Apr 2012, Marc Skinner wrote: > According to your output your Raid1 has failed. It looks like one of > the drives is disconnected or has failed. > > Look at Total Device number = 1, it should be 2 since your doing Raid 1 > with 2 devices. > > ALso - look at State = Clean,degraded, it should say clean > > I would make sure all your data is backed up before you start doing > anything else. Is it possible that it was just set up wrong in the first place? Do you know why it says "Failed Devices: 0"? I don't understand the output, but does this imply that the drive appears as if it had been removed: Number Major Minor RaidDevice State 0 8 2 0 active sync /dev/sda2 1 0 0 1 removed I was assuming it was right and I didn't know how to test it after I first set it up. I'm more aware now about that issue. Thanks. Mike > On 04/01/2012 01:10 PM, Mike Miller wrote: >> I want to be sure that my RAID1 is working properly. What's the best way >> to do that? I tried mdadm --detail (see below) and I guess mdadm thinks >> it is working, but one part surprises me: "Array Size" is different for >> the two disks. Is that normal? The disks are two identical 2TB drives. >> >> Mike >> >> >> $ sudo mdadm --detail /dev/md[01] >> [sudo] password for [user]: /dev/md0: >> Version : 00.90 >> Creation Time : Tue Oct 4 11:45:48 2011 >> Raid Level : raid1 >> Array Size : 1945312384 (1855.19 GiB 1992.00 GB) >> Used Dev Size : 1945312384 (1855.19 GiB 1992.00 GB) >> Raid Devices : 2 >> Total Devices : 1 >> Preferred Minor : 0 >> Persistence : Superblock is persistent >> >> Update Time : Sun Apr 1 12:54:52 2012 >> State : clean, degraded >> Active Devices : 1 >> Working Devices : 1 >> Failed Devices : 0 >> Spare Devices : 0 >> >> UUID : d64b75e8:e8767139:e368bf24:bd0fce41 >> Events : 0.2357380 >> >> Number Major Minor RaidDevice State >> 0 8 1 0 active sync /dev/sda1 >> 1 0 0 1 removed >> /dev/md1: >> Version : 00.90 >> Creation Time : Tue Oct 4 11:46:13 2011 >> Raid Level : raid1 >> Array Size : 8200960 (7.82 GiB 8.40 GB) >> Used Dev Size : 8200960 (7.82 GiB 8.40 GB) >> Raid Devices : 2 >> Total Devices : 1 >> Preferred Minor : 1 >> Persistence : Superblock is persistent >> >> Update Time : Sun Apr 1 00:57:01 2012 >> State : clean, degraded >> Active Devices : 1 >> Working Devices : 1 >> Failed Devices : 0 >> Spare Devices : 0 >> >> UUID : 90b1095c:d6dd36a1:e368bf24:bd0fce41 >> Events : 0.241 >> >> Number Major Minor RaidDevice State >> 0 8 2 0 active sync /dev/sda2 >> 1 0 0 1 removed