Пересобрать массив если один диск в статусе faulty

1. Mark the disk as failed

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

To verify that the disk is failed, check /proc/mdstat:

# cat /proc/mdstat

Personalities : [linear] [multipath] [raid0] [raid1] [raid5] [raid4] [raid6] [raid10]
md0 : active raid1 sda1[0] sdb1[2](F)
      976773168 blocks [2/1] [U_]

md1 : active raid1 sda2[0] sdb2[1]
      976773168 blocks [2/2] [UU]
Failed disk will be marked as “(F)”.


 
2. Remove the disk by mdadm

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

3. Replace the disk
Replace the faulty disk with new one.

4. Copy the partition table to the new disk
Copy the partition table to the new disk (Caution: This sfdisk command will replace the entire partition table on the target disk with that of the source disk – use an alternative command if you need to preserve other partition information):

# sfdisk -d /dev/sda | sfdisk /dev/sdb

5. Create mirror
Create the mirror of the disk:

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

6. Verify
To test the setup, enter the below command:

# /sbin/mdadm --detail /dev/md0

The following command will show the current progress of the recovery of the mirror disk:

# cat /proc/mdstat