iostats – file system to measure I/O
The report consists of three sections.
The first section reports the amount
of user data in
The second section gives the number of messages, the fastest, slowest, and average turn around time and the amount of data involved with each 9P message type. The final section gives an I/O summary for each file used by the program in terms of opens, reads and writes.
Display summary of file I/O incurred by
Start a new shell, displaying all 9P traffic caused by the shell or its children:
iostats -df /fd/1 rc
Poor clock resolution means that large amounts of I/O must be done to get accurate rate figures.
Can be fooled by programs that do fresh mounts outside its purview,
or by the use of names of files with content that can vary by process (e.g.,