Hi Russel, On Sat, 01 Jul 2017 20:40:05 +1000 Russell Coker <russ...@coker.com.au> wrote: > # btrfs replace start -B 3 /dev/sdd2 / > ERROR: ioctl(DEV_REPLACE_START) on '/' returns error: <illegal result value> > # btrfs replace start -B /dev/sdb2 /dev/sdd2 / > ERROR: ioctl(DEV_REPLACE_START) on '/' returns error: <illegal result value> > # btrfs replace start -B /dev/sdc2 /dev/sdd2 / > ERROR: ioctl(DEV_REPLACE_START) on '/' returns error: <illegal result value> > # btrfs replace start -B 1 /dev/sdd2 / > ERROR: ioctl(DEV_REPLACE_START) on '/' returns error: <illegal result value>
I just observed similar symptoms. Check if there is a add/delete/balance/replace/resize running on the file system. In my case, there was a paused balance that I wasn't aware of (since weeks? Months? …?). Cheers, Lukas
