Asynchronous I/O statistics
The PROCAIO section of the nmon recording file contains the asynchronous
I/O process statistics for the background processes.
The section that has the prefix PROCAIO provides the asynchronous I/O
statistics. You can use the -A option to enable recording of this statistics.
When synchronous I/O occurs, the application cannot be processed until the I/O operation is
complete. In contrast, asynchronous I/O operations are run as the background processes and do not
block user applications. The asynchronous I/O operations and application processing can run in
parallel. Therefore, the performance is improved.
The
PROCAIO section contains the following fields:- aioprocs
- Total number of asynchronous I/O processes that are running.
- aiorunning
- Number of asynchronous I/O processes that are using more than 0.1% of CPU.
- aiocpu
- Total CPU consumption by Asynchronous I/O processes per second.