今天进入系统检查了一下raid1的状态发现degraded了，因为做了raid1 samba还是可以访问的。所以打开机箱检查了一下硬盘连接线重新插拔了一下电源线
post自检检查到另一块硬盘。
1.[root@zh888 ~]# mdadm -D /dev/md0
/dev/md0:
Version : 0.90
Creation Time : Fri Sep 2 10:33:19 2011
Raid Level : raid1
Array Size : 78150656 (74.53 GiB 80.03 GB)
Used Dev Size : 78150656 (74.53 GiB 80.03 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Tue Sep 6 11:57:19 2011
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 57319c2a:090717a6:92042ec3:e00720c4
Events : 0.52
Number Major Minor RaidDevice State
0 3 64 0 active sync /dev/hdb
1 0 0 1 removed //居然/dev/hdd丢失了。
2.mdadm /dev/md0 -a /dev/hdb//重新把/dev/hdd加入/dev/md0设备中,然后等待raid1同步到100%状态为clean状态就可以了,如果要查看同步的进度可以用cat /proc/mdstat
[root@zh888 ~]# mdadm -D /dev/md0//最后完成了同步。
/dev/md0:
Version : 0.90
Creation Time : Fri Sep 2 10:33:19 2011
Raid Level : raid1
Array Size : 78150656 (74.53 GiB 80.03 GB)
Used Dev Size : 78150656 (74.53 GiB 80.03 GB)
Raid Devices : 2
Total Devices : 2
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Thu Sep 8 08:56:31 2011
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
UUID : 57319c2a:090717a6:92042ec3:e00720c4
Events : 0.770
Number Major Minor RaidDevice State
0 3 64 0 active sync /dev/hdb
1 22 64 1 active sync /dev/hdd