Date: Mon, 26 Sep 2011 12:08:15 +0000 (UTC) From: Dag-Erling Smorgrav <des@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r225765 - user/des/phybs Message-ID: <201109261208.p8QC8Fc3073602@svn.freebsd.org>
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Author: des Date: Mon Sep 26 12:08:15 2011 New Revision: 225765 URL: http://svn.freebsd.org/changeset/base/225765 Log: Add a man page. Added: user/des/phybs/phybs.1 (contents, props changed) Modified: user/des/phybs/Makefile Modified: user/des/phybs/Makefile ============================================================================== --- user/des/phybs/Makefile Mon Sep 26 11:57:48 2011 (r225764) +++ user/des/phybs/Makefile Mon Sep 26 12:08:15 2011 (r225765) @@ -3,7 +3,6 @@ PROG = phybs CSTD ?= c99 WARNS ?= 6 -MAN = # none LDADD = -lutil DPADD = ${LIBUTIL} Added: user/des/phybs/phybs.1 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ user/des/phybs/phybs.1 Mon Sep 26 12:08:15 2011 (r225765) @@ -0,0 +1,130 @@ +.\"- +.\" Copyright (c) 2010 Dag-Erling Coïdan Smørgrav +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer +.\" in this position and unchanged. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd September 26, 2011 +.Dt PHYBS 1 +.Os +.Sh NAME +.Nm phybs +.Nd reveal a storage device's physical block size +.Sh SYNOPSIS +.Nm +.Op Fl rtw +.Op Fl l Ar minsize +.Op Fl h Ar maxsize +.Op Fl t Ar total +.Ar device +.Sh DESCRIPTION +The +.Nm +utility runs a series of I/O benchmarks designed to reveal a storage +device's physical block size by comparing the performance of small and +large I/O operations at various (mis-)alignments. +.Pp +The +.Nm +utility makes a series of passes with increasing block sizes. In each +pass, it either reads or writes (or both) a number of blocks at +increasing offsets relative to the ideal alignment, which is assumed +to be multiples of the block size. +The results are presented in terms of time elapsed, transactions per +second and kB per second. +.Pp +If the device's physical block size is larger than its logical block +size, peak performance will be obtained when reading or writing +multiples of the physical block size at offsets which are also +multiples of the physical block size, while I/O operations which do +not meet these criteria will be significantly slower. +.Pp +The following options are available: +.Bl -tag -width Fl +.It Fl h Ar maxsize +Specify the maximum block size to test. +This must be a power of two and a multiple of the minimum block size +.Po +see +.Fl l +.Pc . +The default is eight times the minimum block size. +.It Fl l Ar minsize +Specify the minimum block size to test. +This must be a power of two and a multiple of the device's logical +block size. +The default is the device's logical block size. +.It Fl r +Perform read operations. +This is the default. +.It Fl t Ar total +Specify the total amount of data to read or write in each pass. +This must be a power of two and a multiple of the maximum block size +.Po +see +.Fl h +.Pc . +For best results, it should also be significantly larger than the +device's on-board cache. +The default is 128 MB. +.It Fl w +Perform write operations. +.El +.Sh IMPLEMENTATION NOTES +The +.Nm +utility can be used on files as well as raw devices, but the +characteristics of the underlying file system will greatly influence +the results, possibly to the point where they can not reveal anything +of interest about the actual device. +.Pp +The +.Nm +utility reports the benchmark results, but makes no attempt at +interpreting them. +.Sh EXIT STATUS +The +.Nm +utility returns +.Va EX_OK +if the benchmark completed successfully, +.Va EX_USAGE +if the parameters specified on the command line were invalid, +.Va EX_PERM +if the user does not have permission to open the specified device, +.Va EX_IOERR +if it was interrupted by an I/O error, and +.Va EX_OSERR +if it was interrupted for any other reason. +.Sh SEE ALSO +.Xr recoverdisk 1 +.Xr sysexits 3 +.Xr diskinfo 8 +.Sh AUTHORS +.An -nosplit +The +.Nm +utility and this manual page were written by +.An Dag-Erling Sm\(/orgrav Aq des@FreeBSD.org .
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