BTREPLAY man page on Oracle

Man page or keyword search:  
man Server   33470 pages
apropos Keyword Search (all sections)
Output format
Oracle logo
[printable version]

BTREPLAY(8)							   BTREPLAY(8)

       btreplay - recreate IO loads recorded by blktrace

       btreplay [ options ] <dev...>

       The  btrecord  and  btreplay  tools  provide  the ability to record and
       replay IOs captured by the blktrace utility. Attempts are made to main‐
       tain ordering, CPU mappings and time-separation of IOs.

       The  blktrace  utility  provides the ability to collect detailed traces
       from the kernel for each IO processed by the block IO layer. The traces
       provide	a  complete timeline for each IO processed, including detailed
       information concerning when an IO was first received by	the  block  IO
       layer  —	 indicating  the device, CPU number, time stamp, IO direction,
       sector number and IO size (number of sectors). Using this  information,
       one  is	able to replay the IO again on the same machine or another set
       up entirely.

       The basic operating work-flow to replay IOs would be something like:

	   Run blktrace to collect traces. Here you specify the
	   device or devices that you wish to trace and later replay IOs upon.
	   the only traces you are interested in are QUEUE requests —
	   thus,  to save system resources (including storage for traces), one
	   specify the -a queue command line option to blktrace.

	   While blktrace is running, you run the workload that you
	   are interested in.

	   When the work load has completed, you stop the blktrace
	   utility (thus saving all traces over the complete workload).

	   You extract the pertinent IO information from the traces saved by
	   blktrace using the btrecord utility. This will parse
	   each trace file created by blktrace, and crafty IO descriptions
	   to be used in the next phase of the workload processing.

	   Once btrecord has successfully created a series of data
	   files to be processed, you can run the btreplay utility which
	   attempts to generate the same IOs seen during the  sample  workload

       -c <num>
	      Set number of CPUs to use.

       -d <dir>
	      Set  input  directory.   This option requires a single parameter
	      providing the directory name for where input  files  are	to  be
	      found. The default directory is the current directory (.).

	      Find  record  files automatically This option instructs btreplay
	      to go find all the  record  files	 in  the  directory  specified
	      (either via the -d option, or in the default directory (.).

	      Show help and exit.

       -i <basename>
	      Set base name for input files.  Each input file has 3 fields:

		  Device  identifier  (taken  directly from the device name of
		  blktrace output file).

		  btrecord base name — by default ``replay''.

		  The CPU number (again, taken directly from the
		  blktrace output file name).

	      This option requires a single parameter that will	 override  the
	      default name (replay), and replace it with the specified value.

       -I <num>
	      Set  number of iterations to run.	 This option requires a single
	      parameter which specifies the number of times to run through the
	      input files. The default value is 1

       -M <filename>
	      Specify  device mappings.	 This option requires a single parame‐
	      ter which specifies the name of a file contain device  mappings.
	      The  file	 must  be very simply managed, with just two pieces of
	      data per line:

		  The device name on the recorded system (with the '/dev/'
		  removed). Example: /dev/sda would just be sda.

		  The device name on the replay system to use (again,  without
		  '/dev/' path prepended).

	      An  example  file	 for  when  one would map devices /dev/sda and
	      /dev/sdb on the recorded system to dev/sdg and sdh on the replay
	      system would be:

		     sda sdg
		     sdb sdh

	      The only entries in the file that are allowed are these two ele‐
	      ment lines — we do not (yet?) support the notion of blank lines,
	      or comment lines, or the like.

	      The utility allows for multiple -M options to be supplied on the
	      command line.

	      Disable pre-bunch stalls.	 When specified on the	command	 line,
	      all  pre-bunch  stall  indicators	 will  be ignored. IOs will be
	      replayed without inter-bunch delays.

       -x <factor>
	      Specify acceleration factor. Default value is  1	(no  accelera‐

	      Enable verbose output.  When specified on the command line, this
	      option instructs btreplay to store information  concerning  each
	      stall  and  IO operation performed by btreplay. The name of each
	      file so created will be the input file name used with an	exten‐
	      sion  of	.rep appended onto it. Thus, an input file of the name
	      sdab.replay.3 would generate a verbose output file with the name
	      sdab.replay.3.rep in the directory specified for input files.

	      In  addition,  btreplay  will also output to stderr the names of
	      the input files being processed.

	      Show version number and exit.

	      Enable writing during replay.  As a  precautionary  measure,  by
	      default  btreplay	 will  not process write requests. In order to
	      enable btreplay to actually write to devices one must explicitly
	      specify the -W option.

       btreplay	 was  written  by Alan D. Brunelle.  This man page was created
       from the btreplay documentation by Bas Zoetekouw.

       Report bugs to <>

       Copyright © 2007 Alan D. Brunelle, Alan D. Brunelle and Nathan Scott.
       This is free software.  You may redistribute copies  of	it  under  the
       terms	   of	    the	     GNU      General	   Public      License
       <>.	There is NO WARRANTY,  to  the
       extent permitted by law.
       This  manual  page  was	created	 for  Debian by Bas Zoetekouw.	It was
       derived from the documentation provided by the authors and  it  may  be
       used,  distributed and modified under the terms of the GNU General Pub‐
       lic License, version 2.
       On Debian systems, the text of the GNU General Public  License  can  be
       found in /usr/share/common-licenses/GPL-2.

       The full documentation for btreplay can be found in /usr/share/doc/blk‐
       trace on Debian systems.
       blktrace (8), blkparse (1), btrecord (8)

blktrace git-20071207142532    December	 8, 2007		   BTREPLAY(8)

List of man pages available for Oracle

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net