PostgreSQL 12 High Availability Cookbook - Third Edition

How it works...

By default, sar operates in CPU mode. Simply using the command as named; we will receive CPU activity samples for every 10 minutes of the current day. Once sar produces this output, it exits. We must invoke it much as we did with iostat if we want the current data.

In our second example, we've chosen to emulate the iostat output by providing a summary of disk activity every 5 seconds until we cancel the command. The -d argument tells sar to display the disk statistics. Just like iostat, sar accepts two optional parameters for interval and count. As we didn't specify a count, sar will print disk performance every 5 seconds.

The third example is where we finally begin leveraging the real power of sar. If we had examined our ...