Monitoring GPFS I/O performance with the mmpmon command
Use the mmpmon command to monitor GPFS™ performance on the node in which it is run, and other specified nodes.
For more information, see mmpmon command
Next, read all of the following relevant mmpmon topics.
- Overview of mmpmon
The mmpmon facility allows the system administrator to collect I/O statistics from the point of view of GPFS servicing application I/O requests. - Specifying input to the mmpmon command
The input requests to the mmpmon command allow the system administrator to collect I/O statistics per mounted file system (fs_io_s) or for the entire node (io_s). - Display I/O statistics per mounted file system
The fs_io_s input request to the mmpmon command allows the system administrator to collect I/O statistics per mounted file system. - Display I/O statistics for the entire node
The io_s input request to the mmpmon command allows the system administrator to collect I/O statistics for the entire node. - Understanding the node list facility
The node list facility can be used to invoke mmpmon on multiple nodes and gather data from other nodes in the cluster. The following table describes the nlist requests for the mmpmon command. - Reset statistics to zero
The reset request resets the statistics that are displayed with fs_io_s and io_s requests. The reset request does not reset the histogram data, which is controlled and displayed with rhist requests. - Understanding the request histogram facility
Use the mmpmon rhist requests to control the request histogram facility. - Understanding the Remote Procedure Call (RPC) facility
The mmpmon requests that start with rpc_s display an aggregation of execution time taken by RPCs for a time unit, for example the last 10 seconds. The statistics displayed are the average, minimum, and maximum of RPC execution time over the last 60 seconds, 60 minutes, 24 hours, and 30 days. - Displaying mmpmon version
The ver request returns a string containing version information. - Example mmpmon scenarios and how to analyze and interpret their results
This topic is an illustration of how mmpmon is used to analyze I/O data and draw conclusions based on it. - Other information about mmpmon output
When interpreting the results from the mmpmon output there are several points to consider.
Parent topic: Performance monitoring