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hardware and drivers used on the various systems. Given similar
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hardware, Samba should certainly be competitive in speed with other
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600093"></a>Socket Options</h2></div></div><div></div></div><p>
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621406"></a>Socket Options</h2></div></div></div><p>
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There are a number of socket options that can greatly affect the
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performance of a TCP-based server like Samba.
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The socket options that Samba uses are settable both on the command
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line with the <tt class="option">-O</tt> option, or in the <tt class="filename">smb.conf</tt> file.
30
The <a class="indexterm" name="id2600121"></a>socket options section of the <tt class="filename">smb.conf</tt> manual page describes how
30
The <a class="indexterm" name="id2621434"></a>socket options section of the <tt class="filename">smb.conf</tt> manual page describes how
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to set these and gives recommendations.
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Getting the socket options correct can make a big difference to your
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can seriously degrade Samba performance on the loopback adaptor (IP Address 127.0.0.1). It is strongly
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recommended that before specifying any settings for <i class="parameter"><tt>socket options</tt></i> the effect
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first be quantitatively measured on the server being configured.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600182"></a>Read Size</h2></div></div><div></div></div><p>
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The option <a class="indexterm" name="id2600190"></a>read size affects the overlap of disk
47
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621495"></a>Read Size</h2></div></div></div><p>
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The option <a class="indexterm" name="id2621503"></a>read size affects the overlap of disk
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reads/writes with network reads/writes. If the amount of data being
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transferred in several of the SMB commands (currently SMBwrite, SMBwriteX and
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SMBreadbraw) is larger than this value, then the server begins writing
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done as yet to determine the optimal value, and it is likely that the best
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value will vary greatly between systems anyway. A value over 65536 is
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pointless and will cause you to allocate memory unnecessarily.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600220"></a>Max Xmit</h2></div></div><div></div></div><p>
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621533"></a>Max Xmit</h2></div></div></div><p>
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At startup the client and server negotiate a <i class="parameter"><tt>maximum transmit</tt></i> size,
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which limits the size of nearly all SMB commands. You can set the
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maximum size that Samba will negotiate using the <a class="indexterm" name="id2600237"></a>max xmit option
67
maximum size that Samba will negotiate using the <a class="indexterm" name="id2621550"></a>max xmit option
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in <tt class="filename">smb.conf</tt>. Note that this is the maximum size of SMB requests that
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Samba will accept, but not the maximum size that the client will accept.
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The client maximum receive size is sent to Samba by the client and Samba
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clients may perform better with a smaller transmit unit. Trying values
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of less than 2048 is likely to cause severe problems.
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In most cases the default is the best option.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600263"></a>Log Level</h2></div></div><div></div></div><p>
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If you set the log level (also known as <a class="indexterm" name="id2600272"></a>debug level) higher than 2
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621576"></a>Log Level</h2></div></div></div><p>
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If you set the log level (also known as <a class="indexterm" name="id2621585"></a>debug level) higher than 2
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then you may suffer a large drop in performance. This is because the
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server flushes the log file after each operation, which can be quite
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600284"></a>Read Raw</h2></div></div><div></div></div><p>
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The <a class="indexterm" name="id2600292"></a>read raw operation is designed to be an optimized, low-latency
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621597"></a>Read Raw</h2></div></div></div><p>
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The <a class="indexterm" name="id2621605"></a>read raw operation is designed to be an optimized, low-latency
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file read operation. A server may choose to not support it,
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however, and Samba makes support for <a class="indexterm" name="id2600301"></a>read raw optional, with it
85
however, and Samba makes support for <a class="indexterm" name="id2621614"></a>read raw optional, with it
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being enabled by default.
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In some cases clients do not handle <a class="indexterm" name="id2600313"></a>read raw very well and actually
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In some cases clients do not handle <a class="indexterm" name="id2621626"></a>read raw very well and actually
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get lower performance using it than they get using the conventional
92
So you might like to try <a class="indexterm" name="id2600326"></a>read raw = no and see what happens on your
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So you might like to try <a class="indexterm" name="id2621639"></a>read raw = no and see what happens on your
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network. It might lower, raise or not effect your performance. Only
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testing can really tell.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600337"></a>Write Raw</h2></div></div><div></div></div><p>
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The <a class="indexterm" name="id2600345"></a>write raw operation is designed to be an optimized, low-latency
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621650"></a>Write Raw</h2></div></div></div><p>
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The <a class="indexterm" name="id2621658"></a>write raw operation is designed to be an optimized, low-latency
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file write operation. A server may choose to not support it, however, and Samba makes support for
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<a class="indexterm" name="id2600355"></a>write raw optional, with it being enabled by default.
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<a class="indexterm" name="id2621668"></a>write raw optional, with it being enabled by default.
100
Some machines may find <a class="indexterm" name="id2600366"></a>write raw slower than normal write, in which
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Some machines may find <a class="indexterm" name="id2621679"></a>write raw slower than normal write, in which
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case you may wish to change this option.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600377"></a>Slow Logins</h2></div></div><div></div></div><p>
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621690"></a>Slow Logins</h2></div></div></div><p>
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Slow logins are almost always due to the password checking time. Using
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the lowest practical <a class="indexterm" name="id2600386"></a>password level will improve things.
105
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600396"></a>Client Tuning</h2></div></div><div></div></div><p>
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the lowest practical <a class="indexterm" name="id2621699"></a>password level will improve things.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621709"></a>Client Tuning</h2></div></div></div><p>
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Often a speed problem can be traced to the client. The client (for
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example Windows for Workgroups) can often be tuned for better TCP
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performance. Check the sections on the various clients in
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<a href="Other-Clients.html" title="Chapter�38.�Samba and Other CIFS Clients">Samba and Other CIFS Clients</a>.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600417"></a>Samba Performance Problem Due to Changing Linux Kernel</h2></div></div><div></div></div><p>
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<a href="Other-Clients.html" title="Chapter�40.�Samba and Other CIFS Clients">Samba and Other CIFS Clients</a>.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621730"></a>Samba Performance Problem Due to Changing Linux Kernel</h2></div></div></div><p>
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A user wrote the following to the mailing list:
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I am running Gentoo on my server and Samba 2.2.8a. Recently
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My guess is that it is a link layer issue, not an application
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layer problem. Also run ifconfig and verify that the framing
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error, collisions, and so on, look normal for ethernet.
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2600470"></a>Corrupt tdb Files</h2></div></div><div></div></div><p>
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2621783"></a>Corrupt tdb Files</h2></div></div></div><p>
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Our Samba PDC server has been hosting three TB of data to our 500+ users
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[Windows NT/XP] for the last three years using Samba without a problem.
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Today all shares went very slow. Also the main smbd kept
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docs/htmldocs/Samba-HOWTO-Collection/speed.html
