ZFS Fssh_packet_write_wait: Connection to X.X.X.X port 22: Broken pipe

[Jesse Barton]

I am trying to do a zfs send to a remote zfs(FreeBSD) storage system as a offsite backup from another zfs(FreeBSD) storage system. I am able to send snapshots that are very small in size but if the snapshots get any larger the receive stops after X number of MB's, it fluctuates.

Here is the command I am running.

/sbin/zfs send -v -i nas/share@zfs-auto-snap_hourly-2021-04-15-17h00 nas/share@zfs-auto-snap_frequent-2021-04-16-10h45 | ssh -v replicator@X.X.X.X /sbin/zfs receive -v -F offsite-backups/eph/share

I can SSH into the device just fine and I'm not having issues with sending snapshots from a dataset that is 15GB in size. Snapshots are obviously smaller with less changes happening on this dataset. The problem dataset is 12TB in size trying to send snapshots every hour.

Here is my sshd_config

#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PermitTTY yes
#PrintMotd yes
#PrintLastLog yes
TCPKeepAlive yes
#PermitUserEnvironment no
#Compression delayed
ClientAliveInterval 300
ClientAliveCountMax 5
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10:30:100
#PermitTunnel no
#ChrootDirectory none
#UseBlacklist no
#VersionAddendum FreeBSD-20200214

Here is my .ssh/config on the system doing the send

Host *
        IPQoS=throughput
        TCPKeepAlive yes
        ServerAliveInterval 120
        ServerAliveCountMax 5

I seem to have this issue frequently, it will go away with certain systems and I can never pinpoint why.

Help with this issue would be much appreciated!