RAID
●RAID1の作成
mdadm -C /dev/md0 --level 1 --raid-devices 2 --spare-devices 1 /dev/sdc1 /dev/sdd1 /dev/sde1
mdadm -C /dev/md0 --level 4 --raid-devices 3 /dev/sdc1 /dev/sdd1 /dev/sde1
mkfs.xfs /dev/md0
mount /dev/md0 /mnt/b
●情報表示
# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : active raid4 sde1[3](F) sdd1[1] sdc1[0]
200704 blocks super 1.2 level 4, 512k chunk, algorithm 0 [3/2] [UU_]
# mdadm -Q /dev/md0
/dev/md0: 196.03MiB raid4 3 devices, 0 spares. Use mdadm --detail for more detail.
# mdadm -D /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Sat Dec 22 19:53:36 2018
Raid Level : raid4
Array Size : 200704 (196.03 MiB 205.52 MB)
Used Dev Size : 100352 (98.02 MiB 102.76 MB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Update Time : Sat Dec 22 19:59:04 2018
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Chunk Size : 512K
Name : apc01.apdomain:0 (local to host apc01.apdomain)
UUID : a328a331:472f34ed:0e3dccb0:eb10c3ed
Events : 40
Number Major Minor RaidDevice State
0 8 33 0 active sync /dev/sdc1
1 8 49 1 active sync /dev/sdd1
3 8 65 2 active sync /dev/sde1
●ディスクにFAILEDフラグを付ける
mdadm --manage /dev/md0 -f /dev/sdc1
●ディスク追加
mdadm --manage /dev/md0 -a /dev/sdc1
●ディスク削除
mdadm --manage /dev/md0 -r /dev/sdc1
●削除
umount /mnt/b
# mdadm -S /dev/md0
mdadm: stopped /dev/md0
# ls -l /dev/md0
ls: /dev/md0 にアクセスできません: そのようなファイルやディレクトリはありません
# dd if=/dev/zero of=/dev/sdc1
# dd if=/dev/zero of=/dev/sdd1
# dd if=/dev/zero of=/dev/sde1