rsync - is it only needed on the destination?

Yes and no. You only need to enable rsync sharing on the source nas. When you make a backup of a folder via rsync, it only utilizes the rsync CLIENT on the source readynas, and the rsync server on the destination readynas, which contains the actual rsync share/module.

eton wrote:
I noticed that some of my shares that hasn't got rsync enabled got copied by rsync to the destination, when making a backup of Volume C. The destination USB drive/share has got rsync enabled.

This is with one NAS? (are source and USB drive connected to the same NAS)

Say you have two NAS units A and B and run a backup job, NAS A being the source and NAS B the destination. There are two possibilities:

1. Run backup job on NAS A. On NAS B, Rsync (server) service needs to be enabled and rsync needs to be enabled for the target share
2. Run backup job on NAS B. On NAS A, Rsync (server) service needs to be enabled and rsync needs to be enabled for the target share

You used option 1 and backed up the entire volume C. Seeing you were using Rsync as a client on NAS A, the server options specified for your shares on NAS A are irrelevant.

Edit: Ah, I agree with StephenB probably one NAS. In this case you would run the backup job on the NAS and have the Rsync (server) service enabled. In this case Volume C must be the path on the client and the USB drive the path on the server. Even though you are dealing with one NAS the same principle applies. Only the server options specified for the USB drive are relevant.

Thanks, yes I am using rsync on my NAS and backing up to an external USB drive.
Can rsync be switched of for all shares execpt destination? And will the backup job still work?
Could that create other problems with handling the nas?

I see that some of you use a different terminology, for my case > source ~ server and destination ~ client.

If you read mdgm's post carefully, you will see that he uses source, destination, and service. The source and destinations are always the same (NAS A, and NAS B), but where the rsync service needs to be enabled depends on which NAS is doing the backup.

Yes I noticed that. Thanks