Mounting external ZFS volume

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 on SSD CAM/CRC errors

If you encounter lots of CAM/CRC errors when using encrypted ZFS on some SSD drives on FreeBSD, that is caused by TRIM. You need to disable it in boot loader prompt or add below line to /boot/loader.conf: