//
// Any disk performing more than 40 I/Os per second, sustained over
// at least 30 seconds is probably busy
//
delta = 30 seconds;
disk_busy =
    some_inst (
	$disk.dev.total > 40 count/sec
    )
    -> shell 15 mins "Mail -s 'Heavy sustained disk traffic' sysadm </dev/null";

// Try and catch bursts of activity ... more than 60 I/Os per second
// for at least 25% of 8 consecutive 3 second samples
//
delta = 3 sec;
disk_burst =
    some_inst (
	25%_sample (
	    $disk.dev.total @0..7 > 60 count/sec
	)
    )
    -> alarm 5 mins "Disk Burst? " "%i ";

// any SCSI disk controller performing more than 3 Mbytes per sec is busy
//
some_inst $disk.ctl.blktotal * 0.5 > 3 Mbyte/sec
    -> alarm "Busy Disk Controller: " "%i ";