Preparing for ZFS Storage Pool Migration

To migrate a pool, you must first export it. This operation flushes any unwritten data to disk, writes data to the disk indicating that the export is complete, and removes all information about the pool from the system.

If you do not explicitly export the pool but instead remove the disks manually, you can still import the resulting pool on another system. However, you might lose the last few seconds of data transactions. Also, because the devices are no longer present, the pool will appear as UNAVAIL on the original system. By default, the destination system cannot import a pool that has not been explicitly exported. This condition is necessary to prevent you from accidentally importing an active pool that consists of network-attached storage that is still in use on another system.