HP StorageWorks 2000 Series Reference Manual page 173

You can view the following I/O statistics for a selected virtual disk:
The total IOPS and bandwidth for all volumes in the virtual disk
The IOPS and bandwidth for each volume in the virtual disk
To view volume rate statistics.
1. Select Monitor > Statistics > Volume Rate Stats.
2. Select the virtual disk whose statistics you want to view.
Statistics shown are based on host-side activity in the interval since the page was
last refreshed. The page automatically refreshes at a 60-second interval.
You can view the following I/O statistics for volumes of a selected virtual disk:
The Select A Virtual Disk and Volume Menu panels show all virtual disks in the
system and the selected virtual disk's volume name, size, and LUN.
The Details For Virtual Disk Volume panel shows the total number of host read
and write operations, sectors read and written, and queue depth for related host
ports for the selected volume.
The Host Read I/O Size Histogram shows how many host read operations fell
into a particular size range for the selected volume. The I/O ranges are based on
powers of two.
The Host Write I/O Size Histogram shows how many host write operation fell
into a particular size range for the volume. The I/O ranges are based on powers
of two.
The Host Port Details For Volume panel shows the activity for the volume of
each port connected to a host. Queue depth is the number of host-originated
commands currently queued for the port. The last I/O size is the size of the last
read or write host access in sectors. An operation that is not a read or write sets
this value to zero.
To view cumulative statistics for volumes:
1. Select Monitor > Statistics > Cumulative Volume Stats.
2. Select a virtual disk