On Wed, 29 Oct 2008 13:00:25 -0400, Hal Vaughan wrote: > On Wednesday 29 October 2008, Hendrik Boom wrote: >> I got the message (via email) >> >> This is an automatically generated mail message from mdadm running on >> april >> >> A DegradedArray event had been detected on md device /dev/md0. >> >> Faithfully yours, etc. >> >> P.S. The /proc/mdstat file currently contains the following: >> >> Personalities : [raid1] >> md0 : active raid1 hda3[0] >> 242219968 blocks [2/1] [U_] >> >> unused devices: <none> >> >> > You don't mention that you've checked the array with mdadm --detail > /dev/md0. Try that and it will give you some good information.
april:/farhome/hendrik# mdadm --detail /dev/md0 /dev/md0: Version : 00.90.03 Creation Time : Sun Feb 19 10:53:01 2006 Raid Level : raid1 Array Size : 242219968 (231.00 GiB 248.03 GB) Device Size : 242219968 (231.00 GiB 248.03 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Wed Oct 29 13:23:15 2008 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 UUID : 4dc189ba:e7a12d38:e6262cdf:db1beda2 Events : 0.5130704 Number Major Minor RaidDevice State 0 3 3 0 active sync /dev/hda3 1 0 0 1 removed april:/farhome/hendrik# So from this do I conclude that /dev/hda3 is still working, but that it's the other drive (which isn't identified) that has trouble? I'm a bit surprised that none of the messages identifies the other drive, /dev/hdc3. Is this normal? Is that information available somewhere besides the sysadmin's memory? > > I've never used /proc/mdstat because the --detail option gives me more > data in one shot. From what I remember, this is a raid1, right? It > looks like it has 2 devices and one is still working, but I might be > wrong. Again --detail will spell out a lot of this explicitly. > >> Now I gather from what I've googled that somehow I've got to get the >> RAID to reestablish the failed drive by copying from the nonfailed >> drive. I do believe the hardware is basically OK, and that what I've >> got is probably a problem due to a power failure (We've had a lot of >> these recently) or something transient. >> >> (a) How do I do this? > > If a drive has actually failed, then mdadm --remove /dev/md0 /dev/hdxx. > If the drive has not failed, then you need to fail it first with --fail > as an option/switch for mdadm. So presumably the thing to do is mdadm --fail /dev/md0 /dev/hdc3 mdadm --remove /dev/md0 /dev/hdc3 and then mdadm --add/dev/md0 /dev/hdc3 Is the --fail really needed in my case? the --detail option seems to have given /dev/hdc3 the status of "removed" (although it failed to mention is was /dev/hdc3). > >> (b) is hda3 the failed drive, or is it the one that's still working? > > That's one of the things mdadm --detail /dev/md0 will tell you. It will > list the active drives and the failed drives. Well. I'm glad I was paranoid enough to ask. It seems to be the drive that's working. Glas I didn't try to remove and add in *that* one. Thanks, -- hendrik -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]