Thanks Phil,
The --invalid-backup parameter was necessary to get this up and running.
It's now up with the 7th disk as a spare. Shall I run fsck now, or can
I just try to grow again?
proposed grow operation:
mdadm --grow -raid-devices=7 --backup-file=/dev/usb/grow_md127.bak
/dev/md127
mdadm --stop /dev/md127
umount /dev/md127 # not sure if this is necessary
resize2fs /dev/md127
An fsck could help, if any blocks did get moved.
I would not attempt a grow again until you find out why the previous
attempt didn't make progress. Check if mdmon is running, and/or compile
a fresh copy of mdadm from source. If you don't figure it out, you'll
just end up in the same spot again.
Phil
