Hello,
Im experiencing a problem with my Software Raid. It has always running without problems. Since this morning Im seeing this line in the /var/log/syslog: DeviceDisappeared event detected on md device /dev/md0 ls -l /dev/md0 ls: cannot access /dev/md0: No such file or directory the /etc/mdadm/mdadm.conf: ARRAY /dev/md0 metadata=1.2 name=server:0 UUID=b9618cfa:bb8d5746:d9c0e036:c9b5e9ef cat /proc/mdstat is empty :-( The Strange is as following: mdadm -Es ARRAY /dev/md/0 metadata=1.2 UUID=b9618cfa:bb8d5746:d9c0e036:c9b5e9ef name=server:0 ARRAY /dev/md/0 metadata=1.2 UUID=9b19060d:8e418739:fb555db6:8aa82b6c name=server:0 Its an RAID 1 with 2 disks /dev/sdc and /dev/sdd mdadm --examine /dev/sdd /dev/sdd: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : b9618cfa:bb8d5746:d9c0e036:c9b5e9ef Name : server:0 (local to host server) Creation Time : Mon Feb 24 18:47:54 2014 Raid Level : raid1 Raid Devices : 2 Avail Dev Size : 7813775024 (3725.90 GiB 4000.65 GB) Array Size : 3906887360 (3725.90 GiB 4000.65 GB) Used Dev Size : 7813774720 (3725.90 GiB 4000.65 GB) Data Offset : 262144 sectors Super Offset : 8 sectors State : clean Device UUID : afa9d760:f35c3b77:0d9c890c:e8c99faa Update Time : Sun Nov 16 19:27:35 2014 Checksum : 9176e92f - correct Events : 198 Device Role : Active device 1 Array State : AA ('A' == active, '.' == missing) madm --examine /dev/sdc mdadm --examine /dev/sdc /dev/sdc: Magic : a92b4efc Version : 1.2 Feature Map : 0x0 Array UUID : b9618cfa:bb8d5746:d9c0e036:c9b5e9ef Name : server:0 (local to host server) Creation Time : Mon Feb 24 18:47:54 2014 Raid Level : raid1 Raid Devices : 2 Avail Dev Size : 7813775024 (3725.90 GiB 4000.65 GB) Array Size : 3906887360 (3725.90 GiB 4000.65 GB) Used Dev Size : 7813774720 (3725.90 GiB 4000.65 GB) Data Offset : 262144 sectors Super Offset : 8 sectors State : clean Device UUID : 014728f4:c6f041aa:bbec4955:63af2212 Update Time : Sun Nov 16 19:27:35 2014 Checksum : 811507d - correct Events : 198 Device Role : Active device 0 Array State : AA ('A' == active, '.' == missing) It seem like its somehow working, but the device /dev/mdo is gone..Can someone tell me how I can reactivate the SW Raid ?? uname -a Linux server 3.2.0-4-amd64 #1 SMP Debian 3.2.63-2+deb7u1 x86_64 GNU/Linux cat /etc/debian_version 7.7 Cheers, - Pascal