Hello, I have a old PC that I used as a NAS and I recently bought a true server for this purpose (better, more space,…). Now that it is configure, I want to know how can I copy my data from my old to my new, they are both in truenas core. I read this “Move dataset or pool to another server (different number of disk) | TrueNAS Community” but can’t figure how can I do that, since with copying the files with a computer would take some time (10min to detect only 60GB out of 2TB, not including copying). I try using snapshot but I have this error :
Target dataset ‘Valentin disk drives’ does not have snapshots but has data (13159872 bytes used) and replication from scratch is not allowed. Refusing to overwrite existing data." (I send the logs too if you want to dive in).
Thanks for your help !
Logs :
[2024/06/16 14:50:03] INFO [Thread-9] [zettarepl.paramiko.replication_task__task_1] Connected (version 2.0, client OpenSSH_8.8-hpn14v15)
[2024/06/16 14:50:03] INFO [Thread-9] [zettarepl.paramiko.replication_task__task_1] Authentication (publickey) successful!
[2024/06/16 14:50:03] INFO [replication_task__task_1] [zettarepl.replication.pre_retention] Pre-retention destroying snapshots:
[2024/06/16 14:50:03] ERROR [replication_task__task_1] [zettarepl.replication.run] For task ‘task_1’ non-recoverable replication error ReplicationError(“Target dataset ‘Valentin disk drives’ does not have snapshots but has data (13159872 bytes used) and replication from scratch is not allowed. Refusing to overwrite existing data.”)
Will it be faster if I still do “dirty copying” (via a computer) but instead of CTRL+C CTRL+V I use robocopy or another software ?
Replication is the way to go.
All data on your source machine needs to have at least one snapshot (hit add button in snapshots).
Then replication task has to be set up so target data is not read-only. (Which is default)
Once you prove that replication can work, then turn on ssh+netcat in replication to really speed things up.
But nothing is stopping you from doing a rsync or like approach. 
I just did the add snapshot on my source machine, and the state is “PENDING”, it’s normal right ? I have to wait until it’s finished ? I tried to do a replication but it say “0 snapshots found.” so I guess I will give it some times, also read-only is default so I have to disable it. How many time will it take ?
It did the snapshot (pretty quickly, just the time of taking a snack). So it replicate for now, I will update this when it will finish or if there is any error, but it seem like it will be good ! Thanks 
It’s finished, all my files seems to been here, everythings seems fine. Thanks ! I will mark this topic as resolved.