I'm attempting to perform a backup to an external hard drive. Both the native drive and external drive use a BTRFS filesystem. I do this by first creating a read-only snapshot of my home directory:
# btrfs subvolume snapshot -r /home /.snapshots/home/BACKUP
Followed by a send/receive to the backup drive:
# btrfs send /.snapshots/home/BACKUP | btrfs receive /.backup/home
I get this output:
At subvol /.snapshots/home/BACKUP
At subvol BACKUP
ERROR: failed to clone extents to matt/.local/share/Anki2/Matt/collection.anki2: Invalid argument
where the error occurs after a minute or so. I tried with several different snapshots and got the same error on each. Moreover, I couldn't find that file in any of the snapshots. I thought this might be some sort of disk corruption error, so I booted into a USB OS image and ran
# btrfs check --repair /dev/mapper/...
on the unmounted filesystem. This reported no errors. After booting back into the filesystem, I tried the backup again and got the same error. Any thoughts on what could be causing this?
EDIT
As per Emmanuel Rosa's comment, I tried
# btrfs scrub start -B /
which exited without errors. The issue is still present after the scrub.
EDIT 2
I wasn't able to figure out what was wrong with this. I ended up just deleting the local file and then it worked again.
EDIT 3
While deleting files temporarily suspends the issue, new files are often created that create the same error, so this really isn't resolved. sqlite files seem to be particularly problematic.