On 2025-01-11, Roger Price wrote: > root@titan ~ umount /dev/md4 > root@titan ~ mdadm --misc /dev/md4 --stop > root@titan ~ mdadm --manage /dev/md4 --remove /dev/sdb7 > mdadm: hot remove failed for /dev/sdb7: Device or resource busy If I remember well you have to first set the device as faulty with --fail before --remove could be accepted. But if this is the last device you can erase the partition to remove RAID informations.