Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

138 Administering dynamic multipathing (DMP)
Administering DMP using vxdmpadm
The interval and count attributes may be used to specify the interval in seconds
between displaying the I/O statistics, and the number of lines to be displayed. The actual
interval may be smaller than the value specified if insufficient memory is available to
record the statistics.
To disable the gathering of statistics, enter this command:
# vxdmpadm iostat stop
Examples of using the vxdmpadm iostat command
The follow is an example session using the vxdmpadm iostat command. The first
command enables the gathering of I/O statistics:
# vxdmpadm iostat start
The next command displays the current statistics including the accumulated total numbers
of read and write operations and kilobytes read and written, on all paths:
# vxdmpadm iostat show all
cpu usage = 7952us per cpu memory = 8192b
OPERATIONS KBYTES AVG TIME(ms)
PATHNAME READS WRITES READS WRITES READS WRITES
c0t0d0 1088 0 557056 0 0.009542 0.000000
c2t118d0 87 0 44544 0 0.001194 0.000000
c3t118d0 0 0 0 0 0.000000 0.000000
c2t122d0 87 0 44544 0 0.007265 0.000000
c3t122d0 0 0 0 0 0.000000 0.000000
c2t115d0 87 0 44544 0 0.001200 0.000000
c3t115d0 0 0 0 0 0.000000 0.000000
c2t103d0 87 0 44544 0 0.007315 0.000000
c3t103d0 0 0 0 0 0.000000 0.000000
c2t102d0 87 0 44544 0 0.001132 0.000000
c3t102d0 0 0 0 0 0.000000 0.000000
c2t121d0 87 0 44544 0 0.000997 0.000000
c3t121d0 0 0 0 0 0.000000 0.000000
c2t112d0 87 0 44544 0 0.001559 0.000000
c3t112d0 0 0 0 0 0.000000 0.000000
c2t96d0 87 0 44544 0 0.007057 0.000000
c3t96d0 0 0 0 0 0.000000 0.000000
c2t106d0 87 0 44544 0 0.007247 0.000000
c3t106d0 0 0 0 0 0.000000 0.000000
c2t113d0 87 0 44544 0 0.007235 0.000000
c3t113d0 0 0 0 0 0.000000 0.000000
c2t119d0 87 0 44544 0 0.001390 0.000000
c3t119d0 0 0 0 0 0.000000 0.000000
The following command changes the amount of memory that vxdmpadm can use to
accumulate the statistics:
# vxdmpadm iostat start memory=4096
The displayed statistics can be filtered by path name, DMP node name, and enclosure
name (note that the per-CPU memory has changed following the previous command):
# vxdmpadm iostat show pathname=c3t115d0