Proxmox ZFS Pool Setup

The goal of this procedure is to set up a ZFS pool (Zpool) and its subpools on a Proxmox server that doesn't have dedicated disks for storage ZFS.

Prerequisites

This process is being done to a node that has two drives, sized 4TB. We will be setting a 250GB partition on each drive to serve as the local/local-zfs storage in Proxmox. The remaining free space on the drives will be used to create a second Zpool. During the installation of Proxmox we set the hdsize parameter to 250GB. This will ensure it only uses 250GB of the boot drives for the configuration, leaving the rest untouched. After this, we need to use cfdisk to create partitions out of the remaining disk space. We will leave this without a filesystem as ZFS will be installing its filesystem over these partitions in the next step.

Creating the main pool

(The following has been adapted from the results of zpool history on an existing Zpool.)

zpool create -o ashift=12 <pool name> mirror /dev/disk/by-id/disk1-XXXXXXXXXXXXXX-XXXXXXXXXXXXXX-part4 /dev/disk/by-id/disk2-XXXXXXXXXXXXXX-XXXXXXXXXXXXXX-part4
zfs set compression=zstd <pool name>
zfs create <pool name>/vmstorage
zfs create <pool name>/vz-dir
zfs set sync=disabled <pool name>/vmstorage
zfs set atime=on <pool name>
zfs set atime=off <pool name>/vmstorage
zfs set compression=zstd <pool name>/vmstorage
zfs set compression=zstd <pool name>/vz-dir

In the above example, the suffix of -part4 is inferred for demonstrative purposes. Depending on the exact configuration set when installing Proxmox and creating its default local/local-zfs system as well as later using cfdisk, this could be a different partition number.