If you need to perform a data recovery from an external ZFS [zfs] volume you may find those hinds helpful:

  1. Attach encrypted partition where ZFS pool resides with:
    geli attach /dev/your_device_partition
  2. Import ZFS pool at given mountpoint (/mnt/zfs):
    zpool import -af -R /mnt/zfs
  3. Modify mount point location for a given dataset that may have mountpoint set to none what marks it as no mount (note this mountpoint will append to parent mount point location):
    zfs set mountpoint=ROOT zroot/ROOT/default
  4. Mount and mount all pool datasets:
    zfs mount -a
    zfs umount -a
  5. Mount/umount given dataset:
    zfs mount zroot/ROOT/default
  6. You can verify if your ZFS pool is active with:
    zpool status
  7. You can see what ZFS datasets are available with mount points with:
    zfs list

[zfs] https://www.freebsd.org/doc/handbook/zfs.html