You can use the vxdmpadm
iostat
command to gather and display I/O statistics for a specified DMP node, enclosure, path or controller.
To enable the gathering of statistics, enter this command:
# vxdmpadm iostat start
[memory=
size]
To reset the I/O counters to zero, use this command:
The memory
attribute can be used to limit the maximum amount of memory that is used to record I/O statistics for each CPU. The default limit is 32k
(32 kilobytes) per CPU.
To display the accumulated statistics at regular intervals, use the following command:
# vxdmpadm iostat show
{all | dmpnodename=dmp-node
| \
enclosure=enclr-name
| pathname=path-name
| ctlr=
ctlr-name} \
[interval=seconds
[count=N
]]
This command displays I/O statistics for all controllers (all
), or for a specified DMP node, enclosure, path or controller. The statistics displayed are the CPU usage and amount of memory per CPU used to accumulate statistics, the number of read and write operations, the number of kilobytes read and written, and the average time in milliseconds per kilobyte that is read or written.
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:
The follow is an example session using the vxdmpadm
iostat
command. The first command enables the gathering of I/O statistics:
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:
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=c3t115d0s2
cpu usage = 8132us per cpu memory = 4096b
PATHNAME READS WRITES READS WRITES READS WRITES
c3t115d0s2 0 0 0 0 0.000000 0.000000
# vxdmpadm iostat show dmpnodename=c0t0d0s2
cpu usage = 8501us per cpu memory = 4096b
PATHNAME READS WRITES READS WRITES READS WRITES
c0t0d0 s2 1088 0 557056 0 0.009542 0.000000
# vxdmpadm iostat show enclosure=Disk
cpu usage = 8626us per cpu memory = 4096b
PATHNAME READS WRITES READS WRITES READS WRITES
c0t0d0 s2 1088 0 557056 0 0.009542 0.000000
You can also specify the number of times to display the statistics and the time interval. Here the incremental statistics for a path are displayed twice with a 2-second interval:
# vxdmpadm iostat show pathname=c3t115d0s2 interval=2 count=2
cpu usage = 8195us per cpu memory = 4096b
PATHNAME READS WRITES READS WRITES READS WRITES
c3t115d0s2 0 0 0 0 0.000000 0.000000
cpu usage = 59us per cpu memory = 4096b
PATHNAME READS WRITES READS WRITES READS WRITES
c3t115d0s2 0 0 0 0 0.000000 0.000000