Hey Filipe, thanks for the feedback. I ran the command again with -vv. Below are the last commands logged by btrfs receive to stderr: mkfile o2138798-5016457-0 rename leonard/mail/lists/emacs-orgmode/new/1530428589.M675528862P21583Q6R28ec1af3.leonard-xps13 -> o2138802-5207521-0 rename o2138798-5016457-0 -> leonard/mail/lists/emacs-orgmode/new/1530428589.M675528862P21583Q6R28ec1af3.leonard-xps13 utimes leonard/mail/lists/emacs-orgmode/new ERROR: cannot open /mnt/_btrbk_backups/leonard-xps13/@home.20180902T0045/o2138798-5016457-0: No such file or directory The file which is mentioned above has in fact not changed between the parent and current snapshot. I computed further a hash of the file on source volume for parent and current snapshot and target on target volume for parent snapshot. I get the same hash value in all 3 cases, so the parent snapshot was apparently transferred correctly. Note that the folder in which this file is placed contains 96558 files whose sizes sum to 774M. I further observed that the snapshot that previously failed to transfer via send receive could now be sent / received without error. However, the error then occured again for the next snapshot (which has the now successfully transferred one as parent). There may be a race condition that leads to non-deterministic failures. Please let me know if I can help with any further information. Best regards Leonard Filipe Manana <fdmanana@xxxxxxxxx> writes: >> > 1) Machine 1 takes regular snapshots and sends them to machine 2. btrfs >> > btrfs send ... | ssh user@machine2 "btrfs receive /path1" >> > 2) Machine 2 backups all subvolumes stored at /path1 to a second >> > independent btrfs filesystem. Let /path1/rootsnapshot be the first >> > snapshot stored at /path1 (ie. it has no Parent UUID). Let >> > /path1/incrementalsnapshot be a snapshot that has /path1/rootsnapshot >> > as a parent. Then >> > btrfs send -v /path1/rootsnapshot | btrfs receive /path2 >> > works without issues, but >> > btrfs send -v -p /path1/rootsnapshot /path1/incrementalsnapshot | btrfs receive /path2 > > -v is useless. Use -vv, which will dump all commands. > >> > fails as follows: >> > ERROR: chown o257-4639416-0 failed: No such file or directory >> > >> > No error is shown in dmesg. /path1 and /path2 denote two independent >> > btrfs filesystems. >> > >> > Note that there was no issue with transferring incrementalsnapshot from >> > machine 1 to machine 2. No error is shown in dmesg.
