If your problem requires data collection that is not covered by the sar/sadc defaults,
you can start the tools manually. Start the tools manually, for example, when you need a smaller
sampling interval than the default.
About this task
The sampling interval depends on the time period during which performance
problems are seen. You can use a default sampling interval of 10 minutes. If performance problems
occur for a couple of minutes occasionally, shorten the sampling interval to less than a
minute.
Procedure
- To start the sadc command directly, issue a command of the
following form:
/usr/lib64/sa/sadc [options] [interval [count] > <sadc_outfile>
See the sadc man page for details.
For example:
[root@system:]# /usr/lib64/sa/sadc 1 5 > sadc_outfile
[root@system:]# /usr/lib64/sa/sadc -S DISK 10 > sadc_outfile
Omit the count parameter to let sadc sample data until it is stopped.
Use the -S DISK option to collect disk statistics. By default sadc
does not report disks activity to prevent data files from growing too large.
Note: In Ubuntu, the sadc tool is located in the
/usr/lib/sysstat/sadc directory. Hence, issue a command of the following
form:
/usr/lib/sysstat/sadc [options] [interval [count] > <sadc_outfile>
- Extract data and write records by using the sar command.
Use a command of the following
form:
sar -A -f <sadc outfile> > <sar outfile>
For example:
[root@system:]# sar -A -f sadc_outfile > sar_outfile
where:
- -A
- reports all the collected statistics.
- -f
- specifies the binary input file.
The sar command creates a collection of performance
reports from the collected sadc data and writes these reports to an output
file.
Results
To report performance data, include both the sadc and the sar data files with the problem
report.
What to do next
After you collect the diagnostic data, you can complete the following tasks, as appropriate: