Setup problems using mmpmon

The issues associated with the setup of mmpmon command and limitations of this command.

Remember these points when using the mmpmon command:
  • You must have root authority.
  • The GPFS daemon must be active.
  • The input file must contain valid input requests, one per line. When an incorrect request is detected by mmpmon, it issues an error message and terminates.

    Input requests that appear in the input file before the first incorrect request are processed by mmpmon.

  • Do not alter the input file while mmpmon is running.
  • Output from mmpmon is sent to standard output (STDOUT) and errors are sent to standard (STDERR).
  • Up to five instances of mmpmon may run on a given node concurrently. See Monitoring I/O performance with the mmpmon command. For the limitations regarding concurrent usage of mmpmon, see Running mmpmon concurrently from multiple users on the same node.
  • The mmpmon command does not support:
    • Monitoring read requests without monitoring writes, or the other way around.
    • Choosing which file systems to monitor.
    • Monitoring on a per-disk basis.
    • Specifying different size or latency ranges for reads and writes.
    • Specifying different latency values for a given size range.