Follow-up Comment #9, bug #39527 (project grub): In my case the command list works as i described, even without the grub2-install after removing the disk. I don't understand why it's logical that the grow -n 2 and fails if executed right after the grow -n 1 -f command. It's an administrative change of the number of disks in the array, in my opnion that can be changed anytime.
This is the command log, i only modified the cat /proc/mdstat output to include only md0 instead of all 7 array's to make the output easier to read. pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[1] sda1[0] 131008 blocks [2/2] [UU] unused devices: <none> pc12 / # mdadm /dev/md0 --fail /dev/sdb1 mdadm: set /dev/sdb1 faulty in /dev/md0 pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[2](F) sda1[0] 131008 blocks [2/1] [U_] unused devices: <none> pc12 / # mdadm /dev/md0 --remove /dev/sdb1 mdadm: hot removed /dev/sdb1 from /dev/md0 pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sda1[0] 131008 blocks [2/1] [U_] unused devices: <none> pc12 / # mdadm --grow /dev/md0 -n 1 -f pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sda1[0] 131008 blocks [1/1] [U] unused devices: <none> pc12 / # mdadm --grow /dev/md0 -n 2 pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sda1[0] 131008 blocks [2/1] [U_] unused devices: <none> pc12 / # mdadm /dev/md0 --add /dev/sdb1 mdadm: added /dev/sdb1 pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[2] sda1[0] 131008 blocks [2/1] [U_] [=========>...........] recovery = 48.4% (63808/131008) finish=0.0min speed=21269K/sec unused devices: <none> pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[1] sda1[0] 131008 blocks [2/2] [UU] unused devices: <none> pc12 / # grub2-install /dev/sda /usr/sbin/grub2-probe: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. /usr/sbin/grub2-probe: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. Installation finished. No error reported. pc12 / # cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1[1] sda1[0] 131008 blocks [2/2] [UU] unused devices: <none> pc12 / # grub2-probe -t abstraction -d /dev/md0 grub2-probe: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image.. diskfilter mdraid09 pc12 / # _______________________________________________________ Reply to this item at: <http://savannah.gnu.org/bugs/?39527> _______________________________________________ Message sent via/by Savannah http://savannah.gnu.org/ _______________________________________________ Bug-grub mailing list Bug-grub@gnu.org https://lists.gnu.org/mailman/listinfo/bug-grub