# mdadm /dev/md0 -a /dev/sdd2
The result is below.
結果は以下。
# mdadm -D /dev/md0
/dev/md0:
Version : 00.90.01
Creation Time : Thu Feb 16 04:08:56 2006
Raid Level : raid1
Array Size : 71570304 (68.25 GiB 73.29 GB)
Device Size : 71570304 (68.25 GiB 73.29 GB)
Raid Devices : 2
Total Devices : 3
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Wed Feb 22 15:38:03 2006
State : clean
Active Devices : 2
Working Devices : 3
Failed Devices : 0
Spare Devices : 1
Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 8 18 1 active sync /dev/sdb2
2 8 50 -1 spare /dev/sdd2
UUID : 6b188363:5c44202a:110a9034:0012ccef
Events : 0.62706
ディスクのコンカチネーションってmdadmでもLVMでもできそうだけど、LVMでやる方が運用が楽なんかな?