On 02/12/14 08:14 PM, David McGuffey wrote: > Received the following message in mail to root: > > Message 257: > From root at desk4.localdomain Tue Oct 28 07:25:37 2014 > Return-Path: <root at desk4.localdomain> > X-Original-To: root > Delivered-To: root at desk4.localdomain > From: mdadm monitoring <root at desk4.localdomain> > To: root at desk4.localdomain > Subject: DegradedArray event on /dev/md0:desk4 > Date: Tue, 28 Oct 2014 07:25:27 -0400 (EDT) > Status: RO > > This is an automatically generated mail message from mdadm > running on desk4 > > 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 dm-2[1] > 243682172 blocks super 1.1 [2/1] [_U] > bitmap: 2/2 pages [8KB], 65536KB chunk > > md1 : active raid1 dm-3[0] dm-0[1] > 1953510268 blocks super 1.1 [2/2] [UU] > bitmap: 3/15 pages [12KB], 65536KB chunk > > unused devices: <none> > > & q > Held 314 messages in /var/spool/mail/root > You have mail in /var/spool/mail/root > > Ran a madam query against both raid partitions: > > [root at desk4 ~]# mdadm --query --detail /dev/md0 > /dev/md0: > Version : 1.1 > Creation Time : Thu Nov 15 19:24:17 2012 > Raid Level : raid1 > Array Size : 243682172 (232.39 GiB 249.53 GB) > Used Dev Size : 243682172 (232.39 GiB 249.53 GB) > Raid Devices : 2 > Total Devices : 1 > Persistence : Superblock is persistent > > Intent Bitmap : Internal > > Update Time : Tue Dec 2 20:02:55 2014 > State : active, degraded > Active Devices : 1 > Working Devices : 1 > Failed Devices : 0 > Spare Devices : 0 > > Name : desk4.localdomain:0 > UUID : 29f70093:ae78cf9f:0ab7c1cd:e380f50b > Events : 266241 > > Number Major Minor RaidDevice State > 0 0 0 0 removed > 1 253 3 1 active sync /dev/dm-3 > > [root at desk4 ~]# [root at desk4 ~]# mdadm --query --detail /dev/md1 > /dev/md1: > Version : 1.1 > Creation Time : Thu Nov 15 19:24:19 2012 > Raid Level : raid1 > Array Size : 1953510268 (1863.01 GiB 2000.39 GB) > Used Dev Size : 1953510268 (1863.01 GiB 2000.39 GB) > Raid Devices : 2 > Total Devices : 2 > Persistence : Superblock is persistent > > Intent Bitmap : Internal > > Update Time : Tue Dec 2 20:06:21 2014 > State : active > Active Devices : 2 > Working Devices : 2 > Failed Devices : 0 > Spare Devices : 0 > > Name : desk4.localdomain:1 > UUID : 1bef270d:36301a24:7b93c7a9:a2a95879 > Events : 108306 > > Number Major Minor RaidDevice State > 0 253 0 0 active sync /dev/dm-0 > 1 253 1 1 active sync /dev/dm-1 > [root at desk4 ~]# > > Appears to me that device 0 (/dev/dm-2) on md0 has been removed because > of problems. > > This is my first encounter with a raid failure. I suspect I should > replace disk 0 and let the raid rebuild itself. > > Seeking guidance and a good source for the procedures. > > Dave M In short, buy a replacement disk equal or greater size, create matching partitions and then use mdadm to add the replacement partition (of appropriate size) back into the array. An example command to add a replacement partition would be: mdadm --manage /dev/md0 --add /dev/sda1 I strongly recommend creating a virtual machine with a pair of virtual disks and simulating the replacement of the drive before trying it out on your real system. In any case, be sure to have good backups (immediately). -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education?