check_diskio --device=devicename --critical=critical --warning=warning
        Required arguments:
         --device=name,-d name         device name (or mount point)
         --critical=value,-c value     critical number of sectors/s
         --warning=value,-w value      number of sectors/s which generates a warning

        Options
         --help,-h,-?                  this help message
         --reset,-r                    reset the counter
         --silent,-s                   no warnings or critials are issued
         --ssize=size                  specify the sector size in bytes (default 512)
         --verbose,-v                  verbose output
         --version,-V                  print version
         --uom=unit                    unit of measurement:
[root@xen-host8 contrib]# /usr/lib/nagios/plugins/contrib/check_diskio --device=/dev/sda1 --uom=MB --warn=20 --crit=60
Use of uninitialized value in concatenation (.) or string at /usr/lib/nagios/plugins/contrib/check_diskio line 172.
Use of uninitialized value in concatenation (.) or string at /usr/lib/nagios/plugins/contrib/check_diskio line 172.
Use of uninitialized value in numeric lt (<) at /usr/lib/nagios/plugins/contrib/check_diskio line 700.
Use of uninitialized value in addition (+) at /usr/lib/nagios/plugins/contrib/check_diskio line 703.
Use of uninitialized value in numeric lt (<) at /usr/lib/nagios/plugins/contrib/check_diskio line 709.
Use of uninitialized value in subtraction (-) at /usr/lib/nagios/plugins/contrib/check_diskio line 715.
CHECK_DISKIO CRITICAL - sda1 2097152 MBps | WRITE=2097152;20;60 READ=0;20;60 TOTAL=2097152;20;60