6.3.5. Removing a RAID Device

To remove an existing RAID device, first deactivate it by running the following command as root:
mdadm --stop raid_device
Once deactivated, remove the RAID device itself:
mdadm --remove raid_device
Finally, zero superblocks on all devices that were associated with the particular array:
mdadm --zero-superblock component_device

Example 6.5. Removing a RAID device

Assume the system has an active RAID device, /dev/md3, with the following layout (that is, the RAID device created in Example 6.4, “Extending a RAID device”):
~]# mdadm --detail /dev/md3 | tail -n 4
    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
       2       8       33        2      active sync   /dev/sdc1
In order to remove this device, first stop it by typing the following at a shell prompt:
~]# mdadm --stop /dev/md3
mdadm: stopped /dev/md3
Once stopped, you can remove the /dev/md3 device by running the following command:
~]# mdadm --remove /dev/md3
Finally, to remove the superblocks from all associated devices, type:
~]# mdadm --zero-superblock /dev/sda1 /dev/sdb1 /dev/sdc1