Matthias Petermann wrote:
Am I doing something fundamentally wrong here? Or does this require a kernel newer than 9.3?
In order to do this (something I needed as well, but with NTFS for backing up an iscsi-exported photos zvol) you need to patch zfs so that ccd can use zvols as components;
see this thread: http://mail-index.netbsd.org/netbsd-users/2020/02/26/msg024099.html (patch linked here: http://mail-index.netbsd.org/netbsd-users/2020/02/27/msg024123.html)
I'm a little sad that this (or something more convenient) hasn't been included in -9 :-/
I have written a shellscript that lets me mount snapshots of zvols locally for backup purposes if that is interesting, since the process has a number of steps. I run snapshot refresh from cron.
https://git.shangtai.net/staffan/snapshot Staffan