Monitoring Virtual Processors with Command-Line Utilities

You can use the following onstat -g options to monitor virtual processors:

• ath
• glo
• ioq
• rea

onstat -g ath

The onstat -g ath command displays information on system threads and the virtual-processor classes.

onstat -g glo

Use the onstat -g glo command to display information about each virtual processor that is currently running, as well as cumulative statistics for each virtual processor class. For an example of onstat -g glo output, see information on the onstat utility in the IBM Informix Administrator's Reference.

onstat -g ioq

Use the onstat -g ioq option to determine whether you need to allocate additional virtual processors. The command onstat -g ioq displays the length and other statistics about I/O queues.

If the length of the I/O queue is growing, I/O requests are accumulating faster than the AIO virtual processors can process them. If the length of the I/O queue continues to show that I/O requests are accumulating, consider adding AIO virtual processors.

For an example of onstat -g ioq output, see information in the IBM Informix Administrator's Reference.

onstat -g rea

Use the onstat -g rea option to monitor the number of threads in the ready queue. If the number of threads in the ready queue is growing for a class of virtual processors (for example, the CPU class), you might need to add more virtual processors to your configuration.

For an example of onstat -g rea output, see information in the IBM Informix Administrator's Reference.