On Sun, Nov 22, 2015 at 9:59 PM, Nils Steinger <nst@xxxxxxxxxx> wrote: > Hi, > > I recently ran into a problem while trying to back up some of my btrfs > subvolumes over the network: > `btrfs send` works flawlessly on snapshots of most subvolumes, but keeps > failing on snapshots of a certain subvolume — always after sending 15 GiB: > > btrfs send /btrfs/snapshots/home/2015-11-17_03:28:14_BOOT-AUTOSNAPSHOT | > pv | ssh kappa "btrfs receive /mnt/300gb/backups/snapshots/zeta/home/" > At subvol /btrfs/snapshots/home/2015-11-17_03:28:14_BOOT-AUTOSNAPSHOT > At subvol 2015-11-17_03:28:14_BOOT-AUTOSNAPSHOT > ERROR: send ioctl failed with -2: No such file or directory > 15GB 0:34:34 [7,41MB/s] Which kernel version? Try with a 4.3 kernel (or the latest you can, like a 4.2 or 4.1). If it persists, you can create an image of your filesystem like this for example: btrfs-image -c 9 /dev/whatever fs.img The image won't contain your data (it will all be replaced with zeroes) but file and directory names and xattrs will remain untouched (there's an option to sanitize file names, but that might not help debugging what's going on with send). If this is an option for you, you can send me the image for debugging and getting the bug fixed - but please make sure you try a recent kernel first (ideally 4.3) to see if the problem reproduces there, the send code (like the rest of btrfs and the linux kernel) keeps changing between kernel versions (bug fixes, etc). > > I've tried piping the output to /dev/null instead of ssh and got the > same error (again after sending 15 GiB), so this seems to be on the > sending side. > > However, btrfs scrub reports no errors and I don't get any messages in > dmesg when the btrfs send fails. > > What could cause this kind of error? > And is there a way to fix it, preferably without recreating the FS? > > > Regards, > Nils Steinger > -- Filipe David Manana, "Reasonable men adapt themselves to the world. Unreasonable men adapt the world to themselves. That's why all progress depends on unreasonable men." -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
