If a device is taken offline due to a failure that causes errors to be listed in the zpool status output, you can clear the error counts with the zpool clear command. If a device within a pool is loses connectivity and then connectivity is restored, you will need to clear these errors as well.
If specified with no arguments, this command clears all device errors within the pool. For example:
# zpool clear tank
If one or more devices are specified, this command only clears errors associated with the specified devices. For example:
# zpool clear tank c0t5000C500335F95E3d0
For more information about clearing zpool errors, see Clearing Transient or Persistent Device Errors.