SRAW(8) System Manager's Manual SRAW(8)
sraw - benchmark raw scsi I/O performance under linux
sraw scsi-device [ bstart [ bstep ] ]
This program was written because of all of the whining on the SCSI
channel about poor performance of the scsi drivers. This program basi-
cally reads the specified scsi device and measures the throughput.
Note that the filesystem *AND* the buffer cache are bypassed by this
code, this program was designed to benchmark the naked scsi drivers by
themselves without the need to account for the overhead of any other
portion of the kernel.
This program does a series of reads of the disk, of consecutive areas
on the disk. The device is first queried to determine the sector size
for the device, and then the series of reads is begun. About 5.0 Mb is
read from the device, and then the performance numbers are reported.
Note that since the buffer cache is completely bypassed, there is no
need to be concerned about cache hits or anything.
Output of sraw is a set of lines, 4 numbers per line: blocksize,
elapsed time, nblocks and throughput (in bytes per second).
bstart starting block to check different zones on ZBR discs
bstep factor for sequential stepping, default 1. Use 0 for reading
always the same blocks (from cache)
sraw was written by Eric Youngdale.
sraw is available at
Nov 1993 SRAW(8)