Linux 소프트웨어 RAID에서 고장난 하드 디스크를 교체하는 방법

/dev/sda1 + /dev/sdb1 = /dev/md0

/dev/sda2 + /dev/sdb2 = /dev/md1

2 하드 디스크가 고장났는지 어떻게 알 수 있습니까?

If a disk has failed, you will probably find a lot of error messages in the log files, e.g. /var/log/messages or /var/log/syslog.

You can also run

cat /proc/mdstat

and instead of the string [UU] you will see [U_] if you have a degraded RAID1 array.

 

3 장애가 발생한 디스크 제거

To remove /dev/sdb, we will mark /dev/sdb1 and /dev/sdb2 as failed and remove them from their respective RAID arrays (/dev/md0 and /dev/md1).

First we mark /dev/sdb1 as failed:

mdadm --manage /dev/md0 --fail /dev/sdb1

The output of

cat /proc/mdstat

should look like this:

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[2](F)
      24418688 blocks [2/1] [U_]
 
md1 : active raid1 sda2[0] sdb2[1]
      24418688 blocks [2/2] [UU]
 
unused devices: <none>

Then we remove /dev/sdb1 from /dev/md0:

mdadm --manage /dev/md0 --remove /dev/sdb1

The output should be like this:

server1:~# mdadm --manage /dev/md0 --remove /dev/sdb1
mdadm: hot removed /dev/sdb1

And

cat /proc/mdstat

should show this:

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
      24418688 blocks [2/1] [U_]
 
md1 : active raid1 sda2[0] sdb2[1]
      24418688 blocks [2/2] [UU]
 
unused devices: <none>

Now we do the same steps again for /dev/sdb2 (which is part of /dev/md1):

mdadm --manage /dev/md1 --fail /dev/sdb2

cat /proc/mdstat

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
      24418688 blocks [2/1] [U_]
 
md1 : active raid1 sda2[0] sdb2[2](F)
      24418688 blocks [2/1] [U_]
 
unused devices: <none>

mdadm --manage /dev/md1 --remove /dev/sdb2

server1:~# mdadm --manage /dev/md1 --remove /dev/sdb2
mdadm: hot removed /dev/sdb2

cat /proc/mdstat

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0]
      24418688 blocks [2/1] [U_]
 
md1 : active raid1 sda2[0]
      24418688 blocks [2/1] [U_]
 
unused devices: <none>

Then power down the system:

shutdown -h now

and replace the old /dev/sdb hard drive with a new one (it must have at least the same size as the old one - if it's only a few MB smaller than the old one then rebuilding the arrays will fail).

 

4 새 하드 디스크 추가

After you have changed the hard disk /dev/sdb, boot the system.

The first thing we must do now is to create the exact same partitioning as on /dev/sda. We can do this with the command sgdisk from the gdisk package. If you havent installed gdisk yet, run this command to install it on Debian and Ubuntu:

apt-get install gdisk

For RedHat based Linux distributions like CentOS use:

yum install gdisk

and for OpenSuSE use:

yast install gdisk

The next step is optional but recomended. To ensure that you have a backup of the partition scheme, you can use sgdisk to write the partition schemes of both disks into a file. I will store the backup in the /root folder.

sgdisk --backup=/root/sda.partitiontable /dev/sda
sgdisk --backup=/root/sdb.partitiontable /dev/sdb

장애가 발생한 경우 sgdisk 명령의 --load-backup 옵션을 사용하여 파티션 테이블을 복원할 수 있습니다.
이제 파티션 구성표를/dev/sda에서/dev/sdb로 복사합니다.

sgdisk -R /dev/sdb /dev/sda

그런 다음 새 하드 디스크의 GUID를 무작위로 지정하여 고유한지 확인해야 합니다.

sgdisk -G /dev/sdb

당신은 실행할 수 있습니다

sgdisk -p /dev/sda
sgdisk -p /dev/sdb

두 하드 드라이브에 동일한 파티션이 있는지 확인합니다.
다음으로/dev/sdb1을/dev/md0에 추가하고/dev/sdb2를/dev/md1에 추가합니다.

mdadm --manage /dev/md0 --add /dev/sdb1

server1:~# mdadm --manage /dev/md0 --add /dev/sdb1
mdadm: re-added /dev/sdb1

mdadm --manage /dev/md1 --add /dev/sdb2

server1:~# mdadm --manage /dev/md1 --add /dev/sdb2
mdadm: re-added /dev/sdb2

이제 두 어레이(/dev/md0 및/dev/md1)가 동기화됩니다. 운영

cat /proc/mdstat

언제 완료되는지 확인합니다.
동기화하는 동안 출력은 다음과 같습니다.

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[1]
      24418688 blocks [2/1] [U_]
      [=>...................]  recovery =  9.9% (2423168/24418688) finish=2.8min speed=127535K/sec
 
md1 : active raid1 sda2[0] sdb2[1]
      24418688 blocks [2/1] [U_]
      [=>...................]  recovery =  6.4% (1572096/24418688) finish=1.9min speed=196512K/sec
 
unused devices: <none>

동기화가 완료되면 출력은 다음과 같습니다.

server1:~# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[1]
      24418688 blocks [2/2] [UU]
 
md1 : active raid1 sda2[0] sdb2[1]
      24418688 blocks [2/2] [UU]
 
unused devices: <none>

그게 다야, 당신은 성공적으로/dev/sdb를 교체했습니다!