Rsync doesn't copy zvols

[mepey]

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.

[etorix]

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.

@mepey

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.

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.

[mepey]

Thank you.