NAME
getc_putc - program to test hard drive performance.
SYNOPSIS
getc_putc [-d dir] [-s size(KiB)] [-m machine-name] [-u
uid-to-use:gid-to-use] [-g gid-to-use]
DESCRIPTION
This manual page documents briefly the getc_putc, program.
This is a simple adjunct to the bonnie++ benchmark. It is used to test
various ways of doing IO one byte at a time, usually you don’t need to
do enough of this for it to be a performance issue for it to matter
much which way you do it. But sometimes it’s necessary (for example
whan parsing IO from a terminal and then launching another process
which will take over all IO, such as a simple shell).
The real benefits of this are to help settle some arguements about the
performance of such things, and to educate novices about how bad per-
byte IO really is.
OPTIONS
For getc_putc every option is of the form of a hyphen followed by a
letter and then the next parameter contains the value.
-d the directory to use for the tests.
-s the size of the file for byte IO performance measured in
kilobytes. NB You can specify the size in mega-bytes if you add
’m’ to the end of the number.
The default for this test is to test with a 40MiB file. Of the
file only 1/32 of it will be used for write() and read() system
calls (anything else takes too long), and only 1/4 of it will be
used for locked getc() and putc().
-m name of the machine - for display purposes only.
-u user-id to use. When running as root specify the UID to use for
the tests. It is not recommended to use root, so if you really
want to run as root then use -u root. Also if you want to
specify the group to run as then use the user:group format. If
you specify a user by name but no group then the primary group
of that user will be chosen. If you specify a user by number
and no group then the group will be nogroup.
-g group-id to use. Same as using :group for the -u parameter,
just a different way to specify it for compatibility with other
programs.
-q quiet mode. If specified then some of the extra informational
messages will be suppressed. Also the csv data will be the only
output on standard out and the plain text data will be on
standard error. This means you can run getc_putc -q >> file.csv
to record your csv data.
OUTPUT
The primary output is plain-text in 80 columns which is designed to fit
well when pasted into email and which will work well with Braille
displays.
The second type of output is CSV (Comma Seperated Values). This can
easily be imported into any spread-sheet or database program.
For every test the result is a speed in KiB/s. I do not display the
CPU time because it presumably is 99% of the power of a single CPU (or
something very close to that).
AUTHOR
This program, it’s manual page, and the Debian package were written by
Russell Coker <russell@coker.com.au>.
The documentation, the Perl scripts, and all the code for testing the
creation of thousands of files was written by Russell Coker, but the
entire package is under joint copyright with Tim Bray.
SIGNALS
Handles SIGINT and does a cleanup (which may take some time), a second
SIGINT or a SIGQUIT will cause it to immidiately die.
SIGXCPU and SIGXFSZ act like SIGINT.
Ignores SIGHUP.
AVAILABILITY
The source is available from http://www.coker.com.au/bonnie++ .
See http://etbe.coker.com.au/category/benchmark for further
information.
SEE ALSO
bonnie++(8), zcav(8)
getc_putc(8)