LXD pool on a 2 mirrored HDDs - How?

Go to your LXD user and run lxd init

You mean su - lxd?
This won’t work due to lack of permissions

2020/07/19 15: 21: 04.428324 cmd_run.go: 918: WARNING: cannot create user data directory: cannot create “/ var / snap / lxd / common / lxd / snap / lxd / 16100”: mkdir / var / snap / lxd / common / lxd / snap: permission denied
cannot create user data directory: / var / snap / lxd / common / lxd / snap / lxd / 16100: Permission denied

The snap package runs in its own mount namespace, shielding the host from any mount that occurs inside the snap.

zfs list
NAME USED AVAIL REFER MOUNTPOINT
zfs_lxd 85.5K 449G 24K /zfs_lxd

And i think the problem is with mountpoint.

When i create zpool:

zfs list
NAME USED AVAIL REFER MOUNTPOINT
zfs_lxd 85.5K 449G 24K /zfs_lxd

But in on an existing other installation MOUNTPOINT is set to none.

 zfs list
NAME                               USED  AVAIL  REFER  MOUNTPOINT
zfs_lxd                            454K   449G    24K  none
zfs_lxd/containers                  24K   449G    24K  none
zfs_lxd/custom                      24K   449G    24K  none
zfs_lxd/deleted                    120K   449G    24K  none
zfs_lxd/deleted/containers          24K   449G    24K  none
zfs_lxd/deleted/custom              24K   449G    24K  none
zfs_lxd/deleted/images              24K   449G    24K  none
zfs_lxd/deleted/virtual-machines    24K   449G    24K  none
zfs_lxd/images                      24K   449G    24K  none
zfs_lxd/virtual-machines            24K   449G    24K  none