How to delete an mdadm RAID Array

Deleting a software RAID array will result in all data stored in the devices being lost. So be careful when you remove a RAID array, take backups in case needed.

Before you can remove the software RAID array, you need to unmount it.

umount /dev/mdX

Where /dev/mdX is the device name for the RAID device you need to remove.

Find the disk used to create the RAID with the command

mdadm --detail /dev/mdX

Stop the RAID device with the command

mdadm --stop /dev/mdX

Now you need to run the following commands for each storage device that are part of the RAID device.

mdadm --zero-superblock /dev/sdXY

IMPORTANT: you need to run this for each member of the RAID device.

Finally, edit /etc/mdadm/mdadm.conf, and remove the entry for the RAID array.