SOLVED Replication Error. "Refusing to overwrite data"!

[NumberSix]

Hi
I am trying to replicate my system pool to my main storage pool i.e. from a SSC to a HDD. It was working until I tred to get it to replicate snapshots too, now despite rolling back those changes, it won't replicate anymore - at all.
The error message is:

Error
Target dataset 'NAS/System-Backup' does not have snapshots but has data (e.g. 'iocage' and replication from scratch is not allowed. Refusing to overwrite existing data.

It then continues:

Logs
[2021/10/07 14:40:49] ERROR [replication_task__task_1] [zettarepl.replication.run] For task 'task_1' non-recoverable replication error ReplicationError("Target dataset 'NAS/System-Backup' does not have snapshots but has data (e.g. 'iocage' and replication from scratch is not allowed. Refusing to overwrite existing data.")

Can anyone tell me what's going on here and, more importantly, how to fix it please? Incidentally, I generally only work within the GUI so if some CLI work is needed I'd appreciate it if you spell things out very literall mindedly for me - thanks! :)

 

[Kris Moore]

This error is intentional. It means the remote side of the replication has snapshots or data that does not have the same history the sending systems data. If we blow it away, you could be at risk of losing something you wanted to keep on the remote side.

Two ways to handle this.

1. Change destination for replication, to a "fresh" dataset so replication can start from scratch and not delete anything on the remote side.

or

2. In the replication task, enable "Synchronize destination snapshots with source". (Warning, if you do this, the remote side's data will be blown away and you could lose something on that dataset)

 

[NumberSix]

2. In the replication task, enable "Synchronize destination snapshots with source". (Warning, if you do this, the remote side's data will be blown away and you could lose something on that dataset)

Thank you Kris!
I opted for your option 2, since the system is still young (I set up TrueNAS in the spring of this year) and I really never make any changes to the system pool. I just want a backup, 'in case'. So, blowing away the residual data in the destination suits me fine. Once again, thank you so much for identifying the problem and pointing the way out of the woods. Much appreciated.
Cheers!