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.

The fs_io_s (file system I/O statistics) request returns strings containing I/O statistics taken over all mounted file systems as seen by that node, and are presented as total values for each file system. The values are cumulative since the file systems were mounted or since the last reset request, whichever is most recent. When a file system is unmounted, its statistics are lost.

Read and write statistics are recorded separately. The statistics for a given file system are for the file system activity on the node running mmpmon, not the file system in total (across the cluster).

Table 1 describes the keywords for the fs_io_s response, in the order that they appear in the output. These keywords are used only when mmpmon is invoked with the -p flag.

Table 1. Keywords and values for the **mmpmon fs_io_s** response
Keyword	Description
_n_	IP address of the node responding. This is the address by which GPFS knows the node.
_nn_	The hostname that corresponds to the IP address (the _n_ value).
_rc_	Indicates the status of the operation.
_t_	Indicates the current time of day in seconds (absolute seconds since Epoch (1970)).
_tu_	Microseconds part of the current time of day.
_cl_	Name of the cluster that owns the file system.
_fs_	The name of the file system for which data are being presented.
_d_	The number of disks in the file system.
_br_	Total number of bytes read, from both disk and cache.
_bw_	Total number of bytes written, to both disk and cache.
_oc_	Count of open() call requests serviced by GPFS. This also includes creat() call counts.
_cc_	Number of close() call requests serviced by GPFS.
_rdc_	Number of application read requests serviced by GPFS.
_wc_	Number of application write requests serviced by GPFS.
_dir_	Number of readdir() call requests serviced by GPFS.
_iu_	Number of inode updates to disk.