Syncoid failed to run

OpenZFS Sanoid
1

Hello,

I had a setup of pulling in backup of a remote VPS working great for some time. However, it broke suddenly. I am wondering what could be the reason and how do i make sure it doesnt happend again.

The VPS has sanoid setup up as,

[rpool/var/lib]
process_children_only=false
recursive=true
use_template=production

[template_backup]
autoprune=true
autosnap=false
daily=90
hourly=30
monthly=12
yearly=0

[template_production]
autoprune=true
autosnap=true
daily=30
hourly=4
monthly=3

The backup server uses the command,

syncoid --no-sync-snap --recursive '--recvoptions=ux' --sshkey id_ed25519_recvuser --sendoptions '' --recvoptions '' --no-privilege-elevation senduser@vpsip:rpool/var/lib tank/backuphetznersfu/var/lib

and has the following sanoid setup,

[tank/backuphetznersfu/var/lib]
process_children_only=false
recursive=true
use_template=backup


[template_backup]
autoprune=true
autosnap=false
daily=90
hourly=30
monthly=12
yearly=0


[template_production]
autoprune=true
autosnap=true
daily=30

hourly=2
monthly=3

Unfortunately after working well for some time, backup broke up,

Nov 17 04:00:06 nas syncoid[1865557]: INFO: Resuming interrupted zfs send/receive from senduser@vpsip:rpool/var/lib to tank/backuphetznersfu/var/lib (~ UNKNOWN remaining):
Nov 17 04:00:06 nas syncoid[1866532]: cannot resume send: 'rpool/var/lib@autosnap_2025-10-11_21:00:15_hourly' used in the initial send no longer exists
Nov 17 04:00:06 nas syncoid[1866538]: cannot receive: failed to read from stream

What do i need to change in my setup?

2

Looks like you are trying to resume a send of a snapshot that has been pruned by sanoid.

You might try running syncoid with the --no-resume flag for this one.

3

Thanks. What should i change in my config that this doesnt happen again?

4

How often are you running replication?

This means that the hourly snapshot syncoid started a send from got pruned between the first run and when it tried again.