On 2021-01-10 11:34, [email protected] wrote:
I'm trying to transfer a btrfs snapshot via the network.
First attempt: Both NC programs don't exit after the transfer is complete. When
I ctrl-C the sending side, the receiving side exits OK.
btrfs subvolume delete /mnt/rec/snapshots/*
receive side:
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At subvol 0
sending side:
# btrfs send /mnt/send/snapshots/0 | nc -v 127.0.0.1 6790
At subvol /mnt/send/snapshots/0
localhost [127.0.0.1] 6790 (hnmp) open
Second attempt: both nc programs exit ok at snapshot 0,1,2, but snapshot3 fails
halfway, and 4 fails, as 3 is not complete.
receive side:
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At subvol 0
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At snapshot 1
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At snapshot 2
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At snapshot 3
read(net): Connection reset by peer
ERROR: short read from stream: expected 49183 read 10450
# nc -l -p 6790 | btrfs receive /mnt/rec/snapshots
At snapshot 4
ERROR: cannot find parent subvolume
write(stdout): Broken pipe
sending side:
# btrfs send /mnt/send/snapshots/0 | nc -v -c 127.0.0.1 6790
At subvol /mnt/send/snapshots/0
localhost [127.0.0.1] 6790 (hnmp) open
# btrfs send -p /mnt/send/snapshots/0 /mnt/send/snapshots/1 | nc -v -c
127.0.0.1 6790
At subvol /mnt/send/snapshots/1
localhost [127.0.0.1] 6790 (hnmp) open
# btrfs send -p /mnt/send/snapshots/1 /mnt/send/snapshots/2 | nc -v -c
127.0.0.1 6790
At subvol /mnt/send/snapshots/2
localhost [127.0.0.1] 6790 (hnmp) open
# btrfs send -p /mnt/send/snapshots/2 /mnt/send/snapshots/3 | nc -v -c
127.0.0.1 6790
At subvol /mnt/send/snapshots/3
localhost [127.0.0.1] 6790 (hnmp) open
# btrfs send -p /mnt/send/snapshots/3 /mnt/send/snapshots/4 | nc -v -c
127.0.0.1 6790
At subvol /mnt/send/snapshots/4
localhost [127.0.0.1] 6790 (hnmp) open
write(net): Connection reset by peer
Hi,
Haven't used netcat for btrfs send, so I am not sure why you have these
issues. Have you tried mbuffer instead? This is what I use when I don't
need to go over ssh.
Mbuffer[1] allows you to specify remote host and port. It also has an
async buffer so it should be a bit faster too. In fact, it is useful on
a localhost too, for example when sending snaps to a slower local backup
media.
Receiving side:
# mbuffer -I port | btrfs receive /mnt/rec/snapshots
Sending side:
# btrfs send /mnt/send/snapshots/0 | mbuffer -O remotehost:port
Good Luck!
//Forza
[1]https://www.maier-komor.de/mbuffer.html
