====== RAID - mdadm - Remove a disk from an array ======

A disk cannot be removed directly from an array, unless it is failed.

----

===== Mark a disk as failed =====

<WRAP info>
**NOTE:**  This step is not needed if the disk is already in a failed state.
</WRAP>

<code bash>
mdadm --fail /dev/md0 /dev/sda1
</code>

----

===== Remove the disk from the array =====

<code bash>
mdadm --remove /dev/md0 /dev/sda1
</code>

----

===== Fail and Remove a disk in a single step =====

Both of the above actions can be done in a single step:

<code bash>
mdadm /dev/md0 --fail /dev/sda1 --remove /dev/sda1
</code>