stop and start rebuild software raid
# mdadm /dev/md0 -f /dev/sda1 stop the rebuild
mdadm: set /dev/sda1 faulty in /dev/md0
# mdadm /dev/md0 -r /dev/sda1 remove the devise to avoid start rebuild again after reboot
mdadm: hot removed /dev/sda1
# mdadm /dev/md0 -a /dev/sda1 to start rebuild
mdadm: hot added /dev/sda1