Ersetzen einer defekten Festplatte

1. Use
   

   mdadm --manage /dev/md0 -r /dev/sdd

   
   to remove the drive that was marked as faulty from the array.
2. Power down and replace the drive with a good drive.
3. Power up and set the partition table on the new drive to match those of the other drives in the array. Here we used
   

   sfdisk -d /dev/sda | sfdisk /dev/sdd

4. delete superblock on all partitions
   

   mdadm --zero-superblock /dev/sdd2

5. Add the proper partition on the new drive into the array

6. mdadm --manage /dev/md0 -a /dev/sdd2

7. Sit back and wait for the recovery to happen, you can
   

   cat /proc/mdstat

   
   to watch its progress; you should see something like: