io_trace

io_trace

io_trace

Overview

Io_trace system call traces a process and reports the amount of I/O performed to each file, socket or file descriptor (stdin, stdout and stderr). It is both a useful diagnostic tool for tracking down what files are accessed as well as a benchmarking tool to see how much I/O different implementations use.

For example:

jkb$ io_trace -x -S -p /nfs -- w3m http://www.sanger.ac.uk

File: /nfs/users/nfs_j/jkb/.w3m/cookie
Num. open 1
Num. close 1
Num. read 2
Bytes read 260

File: /nfs/users/nfs_j/jkb/.w3m/w3mtmp17758-0.gz
Num. open 1
Num. close 1
Num. write 1
Bytes written 4470

File: /nfs/users/nfs_j/jkb/.netrc
Num. open 1
Num. close 1
Num. read 2
Bytes read 907

File: /nfs/users/nfs_j/jkb/.w3m/history
Num. open 1
Num. close 1
Num. read 2
Bytes read 12390

Usage:

Usage: io_trace [options] filename ... -- command argument ...
e.g.:  io_trace -x -p foo.bam -- samtools view foo.bam X:100-110

Options:
    -p prefix    Only output filenames matching a specific prefix
    -r regexp    Only output filenames matching a specific regexp
    -x           Suppress files with no I/O performed on them
    -S           Suppress stdin/stdout/stderr and sockets
    -z           Show zero values in output

Download and Installation

Code is available from github.

Authors

Sanger Contributors