I am trying to add a new disk to my (quite large) raid 6 array. I currently have nine devices. Here is the output of
mdadm --details /dev/md127:
/dev/md127:
Version : 1.2
Creation Time : Sat Mar 11 00:55:20 2017
Raid Level : raid6
Array Size : 54697266176 (52163.38 GiB 56010.00 GB)
Used Dev Size : 7813895168 (7451.91 GiB 8001.43 GB)
Raid Devices : 9
Total Devices : 9
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Mon Feb 19 15:18:01 2018
State : active
Active Devices : 9
Working Devices : 9
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 512K
Name : mediavault:Storage
UUID : b38ef62a:26310dcf:9d362556:8d70b5f6
Events : 1625234
Number Major Minor RaidDevice State
9 8 96 0 active sync /dev/sdg
1 8 64 1 active sync /dev/sde
2 8 112 2 active sync /dev/sdh
10 8 80 3 active sync /dev/sdf
4 8 160 4 active sync /dev/sdk
5 8 128 5 active sync /dev/sdi
6 8 32 6 active sync /dev/sdc
7 8 48 7 active sync /dev/sdd
8 8 144 8 active sync /dev/sdj
The device I want to add is /dev/sdb. I try to do it via:
mdadm --add /dev/md127 /dev/sdb
mdadm: Cannot open /dev/sdb: Device or resource busy
I checked to see if it was mounted somewhere:
lsblk /dev/sdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 7.3T 0 disk
And apparently nothing.
In the GUI:
It shows up in physical disks. It does not show up in my raid. I can't see it when I select "grow" in the array.
Any suggestions on what I can do?
Other things I've tried:
mdadm --zero-superblock /dev/sdb
mdadm: Couldn't open /dev/sdb for write - not zeroing