Rsync doesn't copy zvols

Hello again,

I’m a little bit confused.

I have 2 servers with TrueNas: server1 and server2.
I have added an rsync task to server1. This also works and copies files from my selected directory to server2. My problem: Almost all files are stored in a zvol that I have included in a VM.

So my question: How do I copy a zvol with rsync? Why is the dataset copied, but not the zvols in it?

Rsync-Task Datasets auf server1:

Datasets auf server1:

If I go to the /mnt/N1 directory in the terminal, the zvol is not displayed either. But when I create a folder in the terminal, it is copied.

I want the zvol to be copied. Does anyone have an idea why this is not the case?

Ps: If I want to do snaphshots, there is a Error with no space available. That space is used by the zvol. It’s a vicious circle.

Rsync does file-based copy. Zvol is block storage: ZFS does not know what file system is used inside the zvol and where actual files are.

Anyway, between two ZFS systems replication is more efficient than rsync.

Then you have made a terrible desgn error. A zvol should never be allocated the whole space; keep 50% available for CoW to do its stuf when using block storage.


Thank you.