*** /dev/null Thu May 18 20:25:21 1995 --- bonnie.1 Thu May 18 20:26:47 1995 *************** *** 0 **** --- 1,68 ---- + .\" The following requests are required for all man pages. + .Dd May 18, 1995 + .Os UNIX + .Dt BONNIE 1 + .Sh NAME + .Nm bonnie + .Nd Performance Test of Filesystem I/O + .Sh SYNOPSIS + .Nm bonnie + .Op Fl d Ar scratch-dir + .Op Fl s Ar size-in-MB + .Op Fl m Ar machine-label + + .Sh DESCRIPTION + .Nm Bonnie + tests the speed of file I/O from standard C library calls. + It reads and writes 8KB blocks to find the maximum sustained + data rate (usually limited by the drive or controller) and additionally + rewrites the file (better simulating normal operating conditions and + quite dependent on drive and OS optimisations). + + The per character read and write tests are generally limited by CPU speed + only on current generation hardware. It takes some 35 SPECint92 to read + or write a file at a rate of 1MB/s using getc() and putc(). + + The seek test results depend on the buffer cache size, since the fraction + of disk blocks that fits into the buffer cache will be found without any + disk operation and will contribute zero seek time samples. + (See + .Sx BUGS + below.) + + .Sh OPTIONS + .Bl -tag -width indent + .It Fl d Ar scratch-dir + Specify the directory where the test file gets written. The default + is the current directory. Make sure there is sufficient free space + available on the partition this directory resides in. + .It Fl s Ar size-in-MB + Specify the size of the test file in MByte. This much space must be + available for the tests to complete. + .It Fl m Ar machine-label + Specify a label to be written in the first column of the result table. + .El + + .Sh SEE ALSO + .Xr iozone 1 , + .Xr iostat 8 + + .Sh AUTHOR + .Nm Bonnie + was written by Tim Bray . + + .Sh BUGS + .Nm Bonnie + tries hard to measure disk performance and not the quality of the + buffer cache implementation. In merged buffer caches common today, + the buffer cache size is often only limited by total RAM on an otherwise + unloaded system. Be sure to use a file at least twice at large as + available RAM to protect against artificially high results. + + There is no way to keep the buffer cache from increasing the reported + seek rate. This is because the fraction of accesses corresponding to the + amount of the file cached, will be done without seeks. + If your buffer cache is half the size of the file used, then half the + requests will be satisfied immediately, and and the seek rate printed + will be twice the actual value. +