double space

I'm running a ZFS raid-z3 zfs pool on a Proxmox node that serves as a backup host. I create snapshots on different Proxmox hosts with ZFS mirror pools and pull them to the backup node. I noticed that the same snapshots of zVOLs are occupying almost twice the storage space on the backup node...

Hi, I don't get it. First I installed a two node cluster according to https://pve.proxmox.com/wiki/DRBD9, but I cannot resize the disk of a VM ("... not implemented ..."), migration works well. So I decided to change the setup according to https://pve.proxmox.com/wiki/DRBD . Now I can resize...