HOWTO+-+Replace+Defective+ZFS+Hard+Disk


 * Run the command "**zpool status**" to find the unavailable hard disk. Assume it is ad0.
 * Run the command "**smartctl -a /dev/ad0**" to find the serial number of the disk. Change the /dev/ad0 with the unavailable disk from the previous step.
 * Shutdown the system and change the defective disk with a new one of the same or greater size. Boot up again.
 * Run the command "**zpool status**" for one more time to check the name of the new hard disk. Probably it got the same name as the removed one.
 * Run the command "**zpool replace  /dev/ad0**"