Disk Performance Attributes

The Disk Performance attributes refer to disk operations such as data transfer rates, average waiting times, and percentage busy.


Avg Serv Average amount of disk time used in milliseconds over the sampling period. For example, in terms of a bank teller queue, it is the time spent at the teller's window. Valid entries can be up to 9999 milliseconds.

Avg Queue Average number of disk requests outstanding during the sampling period. Valid entries are numbers up to 1000.

Avg Wait Average time waiting for disk access expressed in milliseconds. For example, in terms of a bank teller queue, it is the time from when you first join the queue until you advance to the teller window to be serviced. Valid entries can be up to 9999 milliseconds.

Busy Percent The percentage of time a disk has been busy transferring data. Valid entries are whole numbers up to 100, such as 35 for 35%. The Busy Percent value lets you check whether a process is I/O bound. Values greater than 30% usually indicate excessive paging out to disk, or that a process is I/O bound. If the Busy Percent value is high (greater than 30%) and CPU utilization is also high (greater than 80%), your system is probably overloaded and experiencing degradation of performance.

Disk Name The name of the physical disk which might be partitioned. Valid entries are up to 32 letters or numbers.

Disk Name (Unicode) The name of the physical disk which might be partitioned.

System Name The host name of a monitored system. Valid entries are up to 64 letters and numbers.

Timestamp The date and time the agent collects information as set on the monitored system. The timestamp format for SCAN and STR functions is CYYMMDDHHMMSSmmm (as in 1020315064501000 for 03/15/02 06:45:01) where:

C = Century (0 for 20th, 1 for 21st)

Y = Year

M = Month

D = Day

H = Hour

M = Minute

S = Se

m = millisecond

Transfer Rate The number of data transfers per second during a monitoring interval. Valid entries are numbers up to 9999.

Transferred Bytes The total number of kilobytes that have been transferred during the recording interval. The Transferred Bytes count is one indicator of how fast your disk is moving data. It does not account for variables, such as disk format and efficiency of space usage, that also affect the speed of data transfer.