1
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter�45.�Samba Performance Tuning</title><link rel="stylesheet" href="../samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.74.0"><link rel="home" href="index.html" title="The Official Samba 3.4.x HOWTO and Reference Guide"><link rel="up" href="Appendix.html" title="Part�VI.�Reference Section"><link rel="prev" href="Other-Clients.html" title="Chapter�44.�Samba and Other CIFS Clients"><link rel="next" href="ch-ldap-tls.html" title="Chapter�46.�LDAP and Transport Layer Security"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter�45.�Samba Performance Tuning</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="Other-Clients.html">Prev</a>�</td><th width="60%" align="center">Part�VI.�Reference Section</th><td width="20%" align="right">�<a accesskey="n" href="ch-ldap-tls.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="speed"></a>Chapter�45.�Samba Performance Tuning</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Paul</span> <span class="orgname">Dundee Limb Fitting Centre</span> <span class="surname">Cochrane</span></h3><div class="affiliation"><span class="orgname">Dundee Limb Fitting Centre<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:paulc@dth.scot.nhs.uk">paulc@dth.scot.nhs.uk</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="orgname">The Samba Team</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jelmer@samba.org">jelmer@samba.org</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="orgname">Samba Team</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jht@samba.org">jht@samba.org</a>></code></p></div></div></div></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="speed.html#id2690722">Comparisons</a></span></dt><dt><span class="sect1"><a href="speed.html#id2690760">Socket Options</a></span></dt><dt><span class="sect1"><a href="speed.html#id2690857">Read Size</a></span></dt><dt><span class="sect1"><a href="speed.html#id2690902">Max Xmit</a></span></dt><dt><span class="sect1"><a href="speed.html#id2690949">Log Level</a></span></dt><dt><span class="sect1"><a href="speed.html#id2690974">Read Raw</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691041">Write Raw</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691093">Slow Logins</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691116">Client Tuning</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691137">Samba Performance Problem Due to Changing Linux Kernel</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691229">Corrupt tdb Files</a></span></dt><dt><span class="sect1"><a href="speed.html#id2691324">Samba Performance is Very Slow</a></span></dt></dl></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2690722"></a>Comparisons</h2></div></div></div><p>
1
<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter�45.�Samba Performance Tuning</title><link rel="stylesheet" href="../samba.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="The Official Samba 3.4.x HOWTO and Reference Guide"><link rel="up" href="Appendix.html" title="Part�VI.�Reference Section"><link rel="prev" href="Other-Clients.html" title="Chapter�44.�Samba and Other CIFS Clients"><link rel="next" href="ch-ldap-tls.html" title="Chapter�46.�LDAP and Transport Layer Security"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter�45.�Samba Performance Tuning</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="Other-Clients.html">Prev</a>�</td><th width="60%" align="center">Part�VI.�Reference Section</th><td width="20%" align="right">�<a accesskey="n" href="ch-ldap-tls.html">Next</a></td></tr></table><hr></div><div class="chapter" title="Chapter�45.�Samba Performance Tuning"><div class="titlepage"><div><div><h2 class="title"><a name="speed"></a>Chapter�45.�Samba Performance Tuning</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Paul</span> <span class="surname">Cochrane</span></h3><div class="affiliation"><span class="orgname">Dundee Limb Fitting Centre<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:paulc@dth.scot.nhs.uk">paulc@dth.scot.nhs.uk</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">Jelmer</span> <span class="othername">R.</span> <span class="surname">Vernooij</span></h3><div class="affiliation"><span class="orgname">The Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jelmer@samba.org">jelmer@samba.org</a>></code></p></div></div></div></div><div><div class="author"><h3 class="author"><span class="firstname">John</span> <span class="othername">H.</span> <span class="surname">Terpstra</span></h3><div class="affiliation"><span class="orgname">Samba Team<br></span><div class="address"><p><code class="email"><<a class="email" href="mailto:jht@samba.org">jht@samba.org</a>></code></p></div></div></div></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="speed.html#id2696779">Comparisons</a></span></dt><dt><span class="sect1"><a href="speed.html#id2696817">Socket Options</a></span></dt><dt><span class="sect1"><a href="speed.html#id2696914">Read Size</a></span></dt><dt><span class="sect1"><a href="speed.html#id2696958">Max Xmit</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697006">Log Level</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697030">Read Raw</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697097">Write Raw</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697150">Slow Logins</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697173">Client Tuning</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697194">Samba Performance Problem Due to Changing Linux Kernel</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697286">Corrupt tdb Files</a></span></dt><dt><span class="sect1"><a href="speed.html#id2697381">Samba Performance is Very Slow</a></span></dt></dl></div><div class="sect1" title="Comparisons"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2696779"></a>Comparisons</h2></div></div></div><p>
2
2
The Samba server uses TCP to talk to the client, so if you are
3
3
trying to see if it performs well, you should really compare it to
4
4
programs that use the same protocol. The most readily available
20
20
hardware and drivers used on the various systems. Given similar
21
21
hardware, Samba should certainly be competitive in speed with other
23
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2690760"></a>Socket Options</h2></div></div></div><p>
23
</p></div><div class="sect1" title="Socket Options"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2696817"></a>Socket Options</h2></div></div></div><p>
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24
There are a number of socket options that can greatly affect the
25
25
performance of a TCP-based server like Samba.
44
44
can seriously degrade Samba performance on the loopback adaptor (IP Address 127.0.0.1). It is strongly
45
45
recommended that before specifying any settings for <em class="parameter"><code>socket options</code></em>, the effect
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46
first be quantitatively measured on the server being configured.
47
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2690857"></a>Read Size</h2></div></div></div><p>
47
</p></div><div class="sect1" title="Read Size"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2696914"></a>Read Size</h2></div></div></div><p>
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The option <a class="link" href="smb.conf.5.html#READSIZE" target="_top">read size</a> affects the overlap of disk
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49
reads/writes with network reads/writes. If the amount of data being
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50
transferred in several of the SMB commands (currently SMBwrite, SMBwriteX, and
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61
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="id2690902"></a>Max Xmit</h2></div></div></div><p>
64
</p></div><div class="sect1" title="Max Xmit"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2696958"></a>Max Xmit</h2></div></div></div><p>
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65
At startup the client and server negotiate a <em class="parameter"><code>maximum transmit</code></em> size,
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66
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="link" href="smb.conf.5.html#MAXXMIT" target="_top">max xmit</a> option
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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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76
In most cases the default is the best option.
77
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2690949"></a>Log Level</h2></div></div></div><p>
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</p></div><div class="sect1" title="Log Level"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697006"></a>Log Level</h2></div></div></div><p>
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If you set the log level (also known as <a class="link" href="smb.conf.5.html#DEBUGLEVEL" target="_top">debug level</a>) higher than 2,
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then you may suffer a large drop in performance. This is because the
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80
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="id2690974"></a>Read Raw</h2></div></div></div><p>
82
</p></div><div class="sect1" title="Read Raw"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697030"></a>Read Raw</h2></div></div></div><p>
83
83
The <a class="link" href="smb.conf.5.html#READRAW" target="_top">read raw</a> operation is designed to be an optimized, low-latency
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84
file read operation. A server may choose to not support it,
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85
however, and Samba makes support for <a class="link" href="smb.conf.5.html#READRAW" target="_top">read raw</a> optional, with it
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read operations, so you might like to try <a class="link" href="smb.conf.5.html#READRAW" target="_top">read raw = no</a> and see what happens on your
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network. It might lower, raise, or not affect your performance. Only
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testing can really tell.
93
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2691041"></a>Write Raw</h2></div></div></div><p>
93
</p></div><div class="sect1" title="Write Raw"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697097"></a>Write Raw</h2></div></div></div><p>
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94
The <a class="link" href="smb.conf.5.html#WRITERAW" target="_top">write raw</a> operation is designed to be an optimized, low-latency
95
95
file write operation. A server may choose to not support it, however, and Samba makes support for
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<a class="link" href="smb.conf.5.html#WRITERAW" target="_top">write raw</a> optional, with it being enabled by default.
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98
Some machines may find <a class="link" href="smb.conf.5.html#WRITERAW" target="_top">write raw</a> slower than normal write, in which
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99
case you may wish to change this option.
100
</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2691093"></a>Slow Logins</h2></div></div></div><p>
100
</p></div><div class="sect1" title="Slow Logins"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697150"></a>Slow Logins</h2></div></div></div><p>
101
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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="link" href="smb.conf.5.html#PASSWORDLEVEL" target="_top">password level</a> 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="id2691116"></a>Client Tuning</h2></div></div></div><p>
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</p></div><div class="sect1" title="Client Tuning"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697173"></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 class="link" href="Other-Clients.html" title="Chapter�44.�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="id2691137"></a>Samba Performance Problem Due to Changing Linux Kernel</h2></div></div></div><p>
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</p></div><div class="sect1" title="Samba Performance Problem Due to Changing Linux Kernel"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697194"></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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</p><div class="blockquote"><blockquote class="blockquote"><p>
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<a class="indexterm" name="id2691152"></a>
112
<a class="indexterm" name="id2691159"></a>
111
<a class="indexterm" name="id2697209"></a>
112
<a class="indexterm" name="id2697215"></a>
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I am running Gentoo on my server and Samba 2.2.8a. Recently I changed kernel versions from
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<code class="filename">linux-2.4.19-gentoo-r10</code> to <code class="filename">linux-2.4.20-wolk4.0s</code>. Now I have a
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performance issue with Samba. Many of you will probably say, “<span class="quote">Move to vanilla sources!</span>” Well, I
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performance issue with Samba. Many of you will probably say, <span class="quote">“<span class="quote">Move to vanilla sources!</span>”</span> Well, I
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tried that and it didn't work. I have a 100MB LAN and two computers (Linux and Windows 2000). The Linux server
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shares directories with DivX files, the client (Windows 2000) plays them via LAN. Before, when I was running
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the 2.4.19 kernel, everything was fine, but now movies freeze and stop. I tried moving files between the
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</p></blockquote></div><p>
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The answer he was given is:
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</p><div class="blockquote"><blockquote class="blockquote"><p>
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<a class="indexterm" name="id2691201"></a>
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<a class="indexterm" name="id2691208"></a>
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<a class="indexterm" name="id2691215"></a>
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<a class="indexterm" name="id2697258"></a>
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<a class="indexterm" name="id2697264"></a>
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<a class="indexterm" name="id2697271"></a>
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Grab the mii-tool and check the duplex settings on the NIC. My guess is that it is a link layer issue, not an
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application layer problem. Also run ifconfig and verify that the framing error, collisions, and so on, look
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normal for ethernet.
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</p></blockquote></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2691229"></a>Corrupt tdb Files</h2></div></div></div><p>
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<a class="indexterm" name="id2691237"></a>
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<a class="indexterm" name="id2691243"></a>
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<a class="indexterm" name="id2691250"></a>
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</p></blockquote></div></div><div class="sect1" title="Corrupt tdb Files"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697286"></a>Corrupt tdb Files</h2></div></div></div><p>
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<a class="indexterm" name="id2697293"></a>
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<a class="indexterm" name="id2697300"></a>
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<a class="indexterm" name="id2697307"></a>
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Our Samba PDC server has been hosting three TB of data to our 500+ users [Windows NT/XP] for the last three
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years using Samba without a problem. Today all shares went very slow. Also, the main smbd kept spawning new
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processes, so we had 1600+ running SMDB's (normally we average 250). It crashed the SUN E3500 cluster twice.
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<span class="emphasis"><em>Question:</em></span> Is there any method of keeping the *.tdb files in top condition, or
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how can I detect early corruption?
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<a class="indexterm" name="id2691281"></a>
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<a class="indexterm" name="id2691288"></a>
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<a class="indexterm" name="id2697338"></a>
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<a class="indexterm" name="id2697345"></a>
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<span class="emphasis"><em>Answer:</em></span> Yes, run <code class="literal">tdbbackup</code> each time after stopping nmbd and before starting nmbd.
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<span class="emphasis"><em>Question:</em></span> What I also would like to mention is that the service latency seems
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a lot lower than before the locks cleanup. Any ideas on keeping it top notch?
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<span class="emphasis"><em>Answer:</em></span> Yes. Same answer as for previous question!
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</p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2691324"></a>Samba Performance is Very Slow</h2></div></div></div><p>
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<a class="indexterm" name="id2691333"></a>
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</p></div><div class="sect1" title="Samba Performance is Very Slow"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2697381"></a>Samba Performance is Very Slow</h2></div></div></div><p>
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<a class="indexterm" name="id2697389"></a>
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A site reported experiencing very baffling symptoms with MYOB Premier opening and
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accessing its data files. Some operations on the file would take between 40 and
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<a class="indexterm" name="id2691346"></a>
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<a class="indexterm" name="id2691353"></a>
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<a class="indexterm" name="id2697402"></a>
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<a class="indexterm" name="id2697409"></a>
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It turned out that the printer monitor program running on the Windows
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clients was causing the problems. From the logs, we saw activity coming
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through with pauses of about 1 second.
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<a class="indexterm" name="id2691366"></a>
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<a class="indexterm" name="id2691373"></a>
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<a class="indexterm" name="id2697423"></a>
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<a class="indexterm" name="id2697430"></a>
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Stopping the monitor software resulted in the networks access at normal
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(quick) speed. Restarting the program caused the speed to slow down
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again. The printer was a Canon LBP-810 and the relevant task was
added
removed
docs/htmldocs/Samba3-HOWTO/speed.html
