diff options
Diffstat (limited to 'btt/doc/btt.tex')
| -rw-r--r-- | btt/doc/btt.tex | 120 |
1 files changed, 111 insertions, 9 deletions
diff --git a/btt/doc/btt.tex b/btt/doc/btt.tex index 2907554..a3d190b 100644 --- a/btt/doc/btt.tex +++ b/btt/doc/btt.tex @@ -2,7 +2,7 @@ \usepackage{epsfig,placeins} % -% Copyright (C) 2007 Alan D. Brunelle <Alan.Brunelle@hp.com> +% Copyright (C) 2007-2009 Alan D. Brunelle <Alan.Brunelle@hp.com> % % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by @@ -22,7 +22,7 @@ \title{\texttt{btt} User Guide} \author{Alan D. Brunelle (Alan.Brunelle@hp.com)} -\date{30 October 2008} +\date{8 October 2009} \begin{document} \maketitle @@ -316,7 +316,7 @@ IO\footnote{It should be noted that incoming requests either go through: how the larger number of data values for device (8,0) dominates in the overall average. - \item[Active Requests At Q Information] + \newpage\item[Active Requests At Q Information] An important consideration when analyzing block IO schedulers is to know how many requests the scheduler has to work with. The metric @@ -341,6 +341,34 @@ IO\footnote{It should be noted that incoming requests either go through: Average | 17.4 \end{verbatim} + \item[I/O Active Period Information] + + In this subsection data is tabulated showing I/O activity on a + per-device as well across all devices being traced. ``I/O activity'' + is defined as periods of time when the underlying device driver and + device have at least one I/O to work upon. The values presented include: + + \begin{description} + \item[\# Live] Number of periods of ``liveness.'' + \item[Avg. Act] Average length of each period ov ``liveness.'' + \item[Avg. !Act] Aerage length of each non-active period. + \item[\% Live] Percent of total time spent with the driver/device active. + \end{description} + + Here is a sample portion of this type of chart: + +\begin{verbatim} + DEV | # Live Avg. Act Avg. !Act % Live +---------- | ---------- ------------- ------------- ------ + ( 8, 16) | 29 0.909596815 0.094646263 90.87 + ( 8, 32) | 168 0.097848226 0.068231948 59.06 +---------- | ---------- ------------- ------------- ------ + Total Sys | 33 0.799808811 0.082334758 90.92 +\end{verbatim} + + For information on generating data files that can be plotted with + per-device and system-wide I/O activity see section~\ref{sec:o-Z}. + \end{description} \newpage @@ -425,7 +453,7 @@ pdflush 0.000000790 0.000006752 0.247231307 179791 \newpage\section{\label{sec:data-files}Data Files Output} - Besides the averages output by default, the following 3 files are also + Besides the averages output by default, the following 5(+) files are also created with data points which may be plotted. \begin{description} @@ -440,6 +468,14 @@ pdflush 0.000000790 0.000006752 0.247231307 179791 of IO requests submitted to lower layer drivers, for more information see section~\ref{sec:dhist}. + \item[\emph{file}\_mbps\_fp.dat] Provides a set of data for + mb-per-second values each second + - for more information see section~\ref{sec:rstat}. + + \item[\emph{file}\_iops\_fp.dat] Provides a set of data for + I/Os-per-second values each second + - for more information see section~\ref{sec:rstat}. + \end{description} In addition to the default data files output, there are optional data @@ -595,6 +631,43 @@ pdflush 0.000000790 0.000006752 0.247231307 179791 \caption{\label{fig:dhist}D Histogram} \end{figure} +\newpage\section{\label{sec:rstat}Running Stats Files} + +There are two files produced for each of all devices being traced +(prefixed with \emph{sys\_}) and per-device (prefixed with the device +identifier). + +The two files are for reporting I/O rate (I/Os per second - name ends +with \texttt{iops\_fp.dat}) and throughput (MiB per second - name ends +with \texttt{mbps\_fp.dat}). + +The data in the files has two columns:\smallskip + +\begin{tabular}{lll} +\textbf{File Type} & \textbf{X values} & \textbf{Y values}\\\hline +\textbf{iops} & Runtime (seconds) & I/Os per second\\\hline +\textbf{mbps} & Runtime (seconds) & MiB per second\\\hline +\end{tabular} + +As an example: + +\begin{verbatim} +# ls *fp.dat +008,064_iops_fp.dat +008,064_mbps_fp.dat +sys_iops_fp.dat +sys_mbps_fp.dat +\end{verbatim} + +These can be plotted using various tools (e.g., xmgrace as in +figure~\ref{fig:rstats}). + + \begin{figure}[b!] + \leavevmode\centering + \epsfig{file=rstats.eps,width=4.5in} + \caption{\label{fig:rstats}Running Stats} + \end{figure} + \newpage\section{\label{sec:iostat}iostat Data File} \texttt{btt} attempts to produce the results from running an \texttt{iostat -x} command in parallel with the system as it is being @@ -799,7 +872,7 @@ Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s \newpage\section{\label{sec:cmd-line}Command Line} \begin{verbatim} -Usage: btt 2.08 +Usage: btt 2.09 [ -a | --seek-absolute ] [ -A | --all-data ] [ -B <output name> | --dump-blocknos=<output name> ] @@ -828,6 +901,7 @@ Usage: btt 2.08 [ -v | --verbose ] [ -X | --easy-parse-avgs ] [ -z <output name> | --q2d-latencies=<output name> ] +[ -Z | --do-active \end{verbatim} \subsection{\label{sec:o-a}\texttt{--seek-absolute}/\texttt{-a}} @@ -1108,11 +1182,40 @@ UPG 8,16 1.993361748 1.866492147 ARQ 8,16 12.938165321 \end{verbatim} -\subsection{\label{sec:o-z}\texttt{--q2d-latencies}/\texttt{-l}} +\subsection{\label{sec:o-z}\texttt{--q2d-latencies}/\texttt{-z}} This option instructs \texttt{btt} to generate the Q2D latency file discussed in section~\ref{sec:lat-q2d}. +\subsection{\label{sec:o-Z}\texttt{--q2d-latencies}/\texttt{-Z}} + + This option generates per-device (and total system) data files. Each + file contain a data line which resembles a timing graph: low meaning + I/O inactive, high meaning I/O active. A sample section of two ``active'' regions would be: + +\begin{verbatim} +0.000000000 1.0 +0.000025733 1.0 +0.000025733 1.9 +0.000107089 1.9 +0.000107089 1.0 +0.000107089 1.0 +0.005637386 1.0 +0.005637386 1.9 +0.017323909 1.9 +\end{verbatim} + + Which shows an active area from 0.000025733 through + 0.000107089 followed by another at 0.005637386 through + 0.017323909. Figure~\ref{fig:live_plot} shows a sample plot that can + be generated by such data. + +\begin{figure}[b!] +\leavevmode\centering +\epsfig{file=live.eps,width=5.5in} +\caption{\label{fig:live_plot}Sample graph using data from \texttt{-Z}} +\end{figure} + \newpage\section{\label{sec:bno_plot}bno\_plot.py} Included with the distribution is a simple 3D plotting utility based @@ -1127,8 +1230,7 @@ gnuplot\footnote{\texttt{www.gnuplot.info}}, and will enter interactive mode after the image is produced. In this interactive mode one can enter gnuplot commands at the \texttt{'gnuplot>'} prompt, and/or can change the viewpoint within the 3D image by \emph{left-click-hold} and moving -the mouse. A sample screen shot can be seen in figure~\ref{fig:bno_plot} on -page~\pageref{fig:bno_plot}. +the mouse. A sample screen shot can be seen in figure~\ref{fig:bno_plot}. \subsection*{\texttt{bno\_plot.py} Command Line Options} @@ -1159,7 +1261,7 @@ prompt. \end{verbatim} \end{quotation} -\begin{figure}[b] +\begin{figure}[b!] \leavevmode\centering \epsfig{file=bno_plot.eps,width=5.5in} \caption{\label{fig:bno_plot}Sample \texttt{bno\_plot.py} Screen Shot} |