BTREPLAY(8)
NAME
btreplay - recreate IO loads recorded by blktrace
SYNOPSIS
btreplay [ options ] <dev...>
DESCRIPTION
The btrecord and btreplay tools provide the ability to record and
replay IOs captured by the blktrace utility. Attempts are made to maintain 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:
OPTIONS
- -c <num>
--cpus=<num> - Set number of CPUs to use.
- -d <dir>
--input-directory=<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 (.).
- -F
--find-records - 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 (.).
- -h
--help - Show help and exit.
- -i <basename>
--input-base=<basename> - Set base name for input files. Each input file has 3 fields:
- 1.
Device identifier (taken directly from the device name of
- the
blktrace output file).
- 2.
btrecord base name -- by default ``replay''.
- 3.
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>
--iterations=<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>
--map-devs=<filename> - Specify device mappings. This option requires a single parameter 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:
AUTHORS
btreplay was written by Alan D. Brunelle. This man page was created
from the btreplay documentation by Bas Zoetekouw.
REPORTING BUGS
Report bugs to <linux-btrace@vger.kernel.org>
COPYRIGHT
Copyright (C) 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
<http://www.gnu.org/licenses/gpl.html>. 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 Public License, version 2.
On Debian systems, the text of the GNU General Public License can be
found in /usr/share/common-licenses/GPL-2.
SEE ALSO
- The full documentation for btreplay can be found in /usr/share/doc/blktrace on Debian systems.
blktrace (8), blkparse (1), btrecord (8)