How does PBS handle reassigned container volumes?

[crash]

I currently have a container that has an additional volume for persistent data storage, which has about 80G of data on it. This container and the additional volume are backed up by PBS.

mp1: local-zfs:subvol-100-disk-1,mp=/opt,backup=1,size=100G

I am planning on replacing this container with a new one and reassigning the additional volume to the new container, as described here.

pct move-volume 100 mp1 --target-vmid 200 --target-volume mp1

My question is how will PBS handle this reassignment when backing up the new container? Will it see the new VMID and blindly copy everything over? Or will it somehow realize that the data between vmid 100 and 200 are almost entirely the same? If it's the former, is there a way around this?

Thanks.

 

[fba]

PBS uses deduplication for storing backups. All data is stored in chunks. Making a backup, hashes of new chunks are compared to hashes of existing chunks. Only chunks with a not-yet-stored hash are transfered and stored on PBS.
Therefore no extra data copying.