ZFS can display I/O statistics for a given pool using the iostat subcommand. By default, it will display one line of current activity. To display stats every 5 seconds run the following command (cancel with CTRL+C): zpool iostat 5 To view individual disk activities, specify the -v parameter: zpool iostat -v Of course, both can be combined. For more options, see zpool(8). -- Benedict Reuschling <bcr@FreeBSD.org>