Hello - Fedora 22 user (kernel 4.0.4-303.fc22.i686+PAE) using mdadm - v3.3.2 - 21st August 2014. (Of course, I don't have a backup ... 8^) I had a healthy RAID 6 array, and was trying to grow it from 5 partitions of size 1.8 TB to 6 partitions. # mdadm --add /dev/md6 /dev/sdi1 # mdadm --grow --raid-devices=6 --backup-file=/home/gwr/c/grow_md6.bak /dev/md6 The second command threw a bunch of SELinux errors (ah, thank you, SELinux, for always being there to bite me in the ass when I don't expect it ... 8^) about access to /home/gwr/c/grow_md6.bak. The reshape operation sat for many minutes at 0% progress, according to /proc/mdstat. However, the file /home/gwr/c/grow_md6.bak *was* created; it's about 6MB. In an attempt to kick off the reshape operation, I issued: # setenforce 0 to turn off SELinux enforcement. That didn't help - the reshape sat still, showing no progress. Then I issued: # mdadm --stop /dev/md6 which of course interrupted the reshape operation. It also threw up a bunch of error messages, which you can find in the dmesg.txt file found at https://app.box.com/s/3pksam3c7n79anpnzvsrwekzqwtsvlf6 -- look for the words "cut here". It looks like a segfault or other runtime error: [ 796.84193] WARNING: CPU: 0 PID: 1444 at mm/backing-dev.c:372 bdi_unregister+0x38/0x50() I then tried to restart the grow operation, without SELinux' help, and got the error message in the subject. First, I goofed, and tried the assemble without the backup file: # mdadm --assemble /dev/md6 /dev/sdc4 /dev/sdd4 /dev/sdg4 /dev/sdh1 /dev/sdj1 [ 1966.030411] md: md6 stopped. mdadm: Failed to restore critical section for reshape, sorry. # mdadm --assemble /dev/md6 /dev/sdc4 /dev/sdd4 /dev/sdg4 /dev/sdh1 /dev/sdj1 --backup-file=/home/gwr/c/grow_md6.bak [ 2242.492370] md: md6 stopped. mdadm: Failed to restore critical section for reshape, sorry. # mdadm --assemble /dev/md6 /dev/sdc4 /dev/sdd4 /dev/sdg4 /dev/sdh1 /dev/sdj1 /dev/sdi1 --backup-file=/home/gwr/c/grow_md6.bak [ 2403.741995] md: md6 stopped. mdadm: Failed to restore critical section for reshape, sorry. I ran an mdadm --examine on all my RAID partitions; the file is at https://app.box.com/s/9x2n2wc42i1wqzd1ayrt8ta6cyldrr6i. Of note in that file: the "Reshape pos'n" is 0 on all six drives. I take that to mean that the reshape operation never really got started. Is my next step to add the --invalid-backup switch? If not, what recommendations might you have to fix this? Thanks. George -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
