Displaying DASD performance data

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The dasdstat command reports the statistics over time and gather data for individual devices or across all devices. The statistics include performance data about Parallel Access Volume (PAV) and High Performance FICON.

Before you begin

Before you can collect DASD performance statistics, the debug file system must be mounted, see debugfs.

About this task

Use dasdstat to gather DASD performance statistics and to display them.

Examples

The command can be used to get DASD performance statistics across all devices or for individual ones.

To start gathering data for a summary of all available DASDs, issue:
```
# dasdstat -e global
```
To start gathering data for a selected device 0.0.b223, issue:
```
# dasdstat -e dasda 0.0.b223
```
To stop gathering data for a single device, issue:
```
# dasdstat -d dasda
```
To reset statistic counters for device 0.0.b223, issue:
```
# dasdstat -r 0.0.b223
```
To read data statistics for all devices and for a single device respectively, issue:
```
# dasdstat global
# dasdstat dasda
```

Instead of using the dasdstat command, you can access the raw DASD performance data in debugfs. This data can be used, for example, to write scripts that evaluate dedicated DASD performance data.

For more information about accessing raw DASD performance data, see Device Drivers, Features, and Commands, SC33-8411 available at ibm.com/docs/en/linux-on-systems?topic=linuxone-distributions.

What to do next

After you collect the appropriate diagnostic data, you can complete the following tasks: