Starting the monitor

Use the ziomon command to start the monitor.

Figure 1. ziomon syntax

where:

-f or --force: forces the start of data collection even though there is insufficient free disk space.
-l or --size-limit: defines the upper limit of the output files. Must include one of the suffixes M (megabytes), G (gigabytes), or T (terabytes). Note that this value is only a tentative value that can be slightly exceeded.
-i or --interval-length: specifies the elapsed time between writing data to disk in seconds. Defaults to 60 seconds.
-d or --duration: specifies the monitoring duration in minutes. Must be a multiple of the interval length.
-o or --outfile: specifies the prefix for the log file, configuration file, and aggregation file.
<device>: denotes one or more device names separated by blanks. If <device> denotes a device mapper device, ziomon resolves all of its paths, that is, all SCSI devices that are grouped to that multipathing device. For this purpose ziomon uses information that is provided by multipath -l. ziomon then monitors those SCSI devices. The device mapper device itself is not monitored.
-h or --help: displays help information for the command.
-v or --version: displays version information for the command.
-V or --verbose: displays more information for the command.

Examples

Assume that data should be collected for devices /dev/sda, /dev/sdg, and /dev/sdp for 5 minutes. Data is to be sampled every 20 seconds. The collected data size should not exceed 50 MB. The output files should use the basename "trace_data":
```
ziomon -i 20 -d 5 -l 50M -o trace_data /dev/sda /dev/sdg /dev/sdp
```
Assume that data should be collected for a SCSI tape device. To do this, use the corresponding SCSI generic device instead (for example /dev/sg1) since the actual tape device (for example /dev/st0) can be accessed by one process only:
```
ziomon -i 20 -d 5 -l 50M -o scsi_trace_data /dev/sg1
```