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Jun 17, 2009, 2:19:52 PM (16 years ago)
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Herwig Bauernfeind
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Update 3.3 branch to 3.3.5

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    1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 13. Performance, Reliability, and Availability</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="Samba-3 by Example"><link rel="up" href="RefSection.html" title="Part III. Reference Section"><link rel="prev" href="DomApps.html" title="Chapter 12. Integrating Additional Services"><link rel="next" href="ch14.html" title="Chapter 14. Samba Support"></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 13. Performance, Reliability, and Availability</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="DomApps.html">Prev</a> </td><th width="60%" align="center">Part III. Reference Section</th><td width="20%" align="right"> <a accesskey="n" href="ch14.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="HA"></a>Chapter 13. Performance, Reliability, and Availability</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="HA.html#id2618932">Introduction</a></span></dt><dt><span class="sect1"><a href="HA.html#id2619019">Dissection and Discussion</a></span></dt><dt><span class="sect1"><a href="HA.html#id2619492">Guidelines for Reliable Samba Operation</a></span></dt><dd><dl><dt><span class="sect2"><a href="HA.html#id2619520">Name Resolution</a></span></dt><dt><span class="sect2"><a href="HA.html#id2619995">Samba Configuration</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620323">Use and Location of BDCs</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620398">Use One Consistent Version of MS Windows Client</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620420">For Scalability, Use SAN-Based Storage on Samba Servers</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620470">Distribute Network Load with MSDFS</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620524">Replicate Data to Conserve Peak-Demand Wide-Area Bandwidth</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620570">Hardware Problems</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620728">Large Directories</a></span></dt></dl></dd><dt><span class="sect1"><a href="HA.html#id2620832">Key Points Learned</a></span></dt></dl></div><p>
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     1<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 13. Performance, Reliability, and Availability</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="Samba-3 by Example"><link rel="up" href="RefSection.html" title="Part III. Reference Section"><link rel="prev" href="DomApps.html" title="Chapter 12. Integrating Additional Services"><link rel="next" href="ch14.html" title="Chapter 14. Samba Support"></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 13. Performance, Reliability, and Availability</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="DomApps.html">Prev</a> </td><th width="60%" align="center">Part III. Reference Section</th><td width="20%" align="right"> <a accesskey="n" href="ch14.html">Next</a></td></tr></table><hr></div><div class="chapter" lang="en"><div class="titlepage"><div><div><h2 class="title"><a name="HA"></a>Chapter 13. Performance, Reliability, and Availability</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="HA.html#id2618959">Introduction</a></span></dt><dt><span class="sect1"><a href="HA.html#id2619057">Dissection and Discussion</a></span></dt><dt><span class="sect1"><a href="HA.html#id2619530">Guidelines for Reliable Samba Operation</a></span></dt><dd><dl><dt><span class="sect2"><a href="HA.html#id2619557">Name Resolution</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620033">Samba Configuration</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620360">Use and Location of BDCs</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620435">Use One Consistent Version of MS Windows Client</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620457">For Scalability, Use SAN-Based Storage on Samba Servers</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620507">Distribute Network Load with MSDFS</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620562">Replicate Data to Conserve Peak-Demand Wide-Area Bandwidth</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620607">Hardware Problems</a></span></dt><dt><span class="sect2"><a href="HA.html#id2620755">Large Directories</a></span></dt></dl></dd><dt><span class="sect1"><a href="HA.html#id2620859">Key Points Learned</a></span></dt></dl></div><p>
     2        <a class="indexterm" name="id2618921"></a>
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     4        <a class="indexterm" name="id2618935"></a>
    55        Well, you have reached one of the last chapters of this book. It is customary to attempt
    66        to wrap up the theme and contents of a book in what is generally regarded as the
    … …  
    1111        </p><div class="blockquote"><table border="0" width="100%" cellspacing="0" cellpadding="0" class="blockquote" summary="Block quote"><tr><td width="10%" valign="top"> </td><td width="80%" valign="top"><p>
    1212        In a world so full of noise, how can the sparrow be heard?
    13         </p></td><td width="10%" valign="top"> </td></tr><tr><td width="10%" valign="top"> </td><td colspan="2" align="right" valign="top">--<span class="attribution">Anonymous</span></td></tr></table></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2618932"></a>Introduction</h2></div></div></div><p>
    14         <a class="indexterm" name="id2618940"></a>
     13        </p></td><td width="10%" valign="top"> </td></tr><tr><td width="10%" valign="top"> </td><td colspan="2" align="right" valign="top">--<span class="attribution">Anonymous</span></td></tr></table></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2618959"></a>Introduction</h2></div></div></div><p>
     14        <a class="indexterm" name="id2618967"></a>
    1515        The sparrow is a small bird whose sounds are drowned out by the noise of the busy
    1616        world it lives in. Likewise, the simple steps that can be taken to improve the
    … …  
    2121        custom tools and methods. Only passing comments are offered concerning these methods.
    2222        </p><p>
    23         <a class="indexterm" name="id2618960"></a>
    24         <a class="indexterm" name="id2618967"></a>
    25         <a class="indexterm" name="id2618974"></a>
     23        <a class="indexterm" name="id2618997"></a>
     24        <a class="indexterm" name="id2619004"></a>
     25        <a class="indexterm" name="id2619011"></a>
    2626<a class="ulink" href="http://www.google.com/search?hl=en&amp;lr=&amp;ie=ISO-8859-1&amp;q=samba+cluster&amp;btnG=Google+Search" target="_top">A search</a>
    2727        for &#8220;<span class="quote">samba cluster</span>&#8221; produced 71,600 hits. And a search for &#8220;<span class="quote">highly available samba</span>&#8221;
    … …  
    3030        availability, reliability, and scalability are of vital interest to corporate network users.
    3131        </p><p>
    32         <a class="indexterm" name="id2619007"></a>
     32        <a class="indexterm" name="id2619044"></a>
    3333        So without further background, you can review a checklist of simple steps that
    3434        can be taken to ensure acceptable network performance while keeping costs of ownership
    3535        well under control.
    36         </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2619019"></a>Dissection and Discussion</h2></div></div></div><p>
    37         <a class="indexterm" name="id2619027"></a>
    38         <a class="indexterm" name="id2619034"></a>
     36        </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2619057"></a>Dissection and Discussion</h2></div></div></div><p>
     37        <a class="indexterm" name="id2619065"></a>
     38        <a class="indexterm" name="id2619071"></a>
    3939        If it is your purpose to get the best mileage out of your Samba servers, there is one rule that
    4040        must be obeyed. If you want the best, keep your implementation as simple as possible. You may
    … …  
    4545        complex ones.
    4646        </p><p>
    47         <a class="indexterm" name="id2619056"></a>
    48         <a class="indexterm" name="id2619063"></a>
     47        <a class="indexterm" name="id2619093"></a>
     48        <a class="indexterm" name="id2619100"></a>
    4949        Problems reported by users fall into three categories: configurations that do not work, those
    5050        that have broken behavior, and poor performance. The term <span class="emphasis"><em>broken behavior</em></span>
    … …  
    5555        and at other times not listing them even though the machines are in use on the network.
    5656        </p><p>
    57         <a class="indexterm" name="id2619090"></a>
    58         <a class="indexterm" name="id2619097"></a>
    59         <a class="indexterm" name="id2619104"></a>
    60         <a class="indexterm" name="id2619111"></a>
    61         <a class="indexterm" name="id2619118"></a>
    62         <a class="indexterm" name="id2619124"></a>
     57        <a class="indexterm" name="id2619128"></a>
     58        <a class="indexterm" name="id2619134"></a>
     59        <a class="indexterm" name="id2619141"></a>
     60        <a class="indexterm" name="id2619148"></a>
     61        <a class="indexterm" name="id2619155"></a>
     62        <a class="indexterm" name="id2619162"></a>
    6363        A significant number of reports concern problems with the <code class="literal">smbfs</code> file system
    6464        driver that is part of the Linux kernel, not part of Samba. Users continue to interpret that
    … …  
    7171        Samba and are really foreign to it.
    7272        </p><p>
    73         <a class="indexterm" name="id2619185"></a>
     73        <a class="indexterm" name="id2619222"></a>
    7474        The new project, <code class="literal">cifsfs</code>, is destined to replace <code class="literal">smbfs</code>.
    7575        It, too, is not part of Samba, even though one of the Samba Team members is a prime mover in
    … …  
    7878        Table 13.1 lists typical causes of:
    7979        </p><div class="itemizedlist"><ul type="disc"><li><p>Not Working (NW)</p></li><li><p>Broken Behavior (BB)</p></li><li><p>Poor Performance (PP)</p></li></ul></div><div class="table"><a name="ProbList"></a><p class="title"><b>Table 13.1. Effect of Common Problems</b></p><div class="table-contents"><table summary="Effect of Common Problems" border="1"><colgroup><col align="left"><col align="center"><col align="center"><col align="center"></colgroup><thead><tr><th align="left"><p>Problem</p></th><th align="center"><p>NW</p></th><th align="center"><p>BB</p></th><th align="center"><p>PP</p></th></tr></thead><tbody><tr><td align="left"><p>File locking</p></td><td align="center"><p>-</p></td><td align="center"><p>X</p></td><td align="center"><p>-</p></td></tr><tr><td align="left"><p>Hardware problems</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td></tr><tr><td align="left"><p>Incorrect authentication</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>-</p></td></tr><tr><td align="left"><p>Incorrect configuration</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td></tr><tr><td align="left"><p>LDAP problems</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>-</p></td></tr><tr><td align="left"><p>Name resolution</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td></tr><tr><td align="left"><p>Printing problems</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>-</p></td></tr><tr><td align="left"><p>Slow file transfer</p></td><td align="center"><p>-</p></td><td align="center"><p>-</p></td><td align="center"><p>X</p></td></tr><tr><td align="left"><p>Winbind problems</p></td><td align="center"><p>X</p></td><td align="center"><p>X</p></td><td align="center"><p>-</p></td></tr></tbody></table></div></div><br class="table-break"><p>
    80         <a class="indexterm" name="id2619479"></a>
     80        <a class="indexterm" name="id2619516"></a>
    8181        It is obvious to all that the first requirement (as a matter of network hygiene) is to eliminate
    8282        problems that affect basic network operation. This book has provided sufficient working examples
    8383        to help you to avoid all these problems.
    84         </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2619492"></a>Guidelines for Reliable Samba Operation</h2></div></div></div><p>
    85         <a class="indexterm" name="id2619501"></a>
    86         <a class="indexterm" name="id2619508"></a>
     84        </p></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2619530"></a>Guidelines for Reliable Samba Operation</h2></div></div></div><p>
     85        <a class="indexterm" name="id2619538"></a>
     86        <a class="indexterm" name="id2619545"></a>
    8787        Your objective is to provide a network that works correctly, can grow at all times, is resilient
    8888        at times of extreme demand, and can scale to meet future needs. The following subject areas provide
    8989        pointers that can help you today.
    90         </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2619520"></a>Name Resolution</h3></div></div></div><p>
     90        </p><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2619557"></a>Name Resolution</h3></div></div></div><p>
    9191        There are three basic current problem areas: bad hostnames, routed networks, and network collisions.
    9292        These are covered in the following discussion.
    93         </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619531"></a>Bad Hostnames</h4></div></div></div><p>
    94                 <a class="indexterm" name="id2619539"></a>
    95                 <a class="indexterm" name="id2619548"></a>
    96                 <a class="indexterm" name="id2619555"></a>
    97                 <a class="indexterm" name="id2619562"></a>
    98                 <a class="indexterm" name="id2619569"></a>
     93        </p><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619568"></a>Bad Hostnames</h4></div></div></div><p>
     94                <a class="indexterm" name="id2619576"></a>
     95                <a class="indexterm" name="id2619586"></a>
     96                <a class="indexterm" name="id2619592"></a>
     97                <a class="indexterm" name="id2619599"></a>
     98                <a class="indexterm" name="id2619606"></a>
    9999                When configured as a DHCP client, a number of Linux distributions set the system hostname
    100100                to <code class="constant">localhost</code>. If the parameter <em class="parameter"><code>netbios name</code></em> is not
    … …  
    108108                correctly.
    109109                </p><p>
    110                 <a class="indexterm" name="id2619624"></a>
     110                <a class="indexterm" name="id2619661"></a>
    111111                A few sites have tried to name Windows clients and Samba servers with a name that begins
    112112                with the digits 1-9. This does not work either because it may result in the client or
    113113                server attempting to use that name as an IP address.
    114114                </p><p>
    115                 <a class="indexterm" name="id2619638"></a>
    116                 <a class="indexterm" name="id2619647"></a>
     115                <a class="indexterm" name="id2619675"></a>
     116                <a class="indexterm" name="id2619684"></a>
    117117                A Samba server called <code class="constant">FRED</code> in a NetBIOS domain called <code class="constant">COLLISION</code>
    118118                in a network environment that is part of the fully-qualified Internet domain namespace known
    … …  
    123123                fails given that you probably do not have this in your DNS namespace.
    124124                </p><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
    125                 <a class="indexterm" name="id2619691"></a>
    126                 <a class="indexterm" name="id2619700"></a>
    127                 <a class="indexterm" name="id2619707"></a>
     125                <a class="indexterm" name="id2619728"></a>
     126                <a class="indexterm" name="id2619738"></a>
     127                <a class="indexterm" name="id2619744"></a>
    128128                An Active Directory realm called <code class="constant">collision.parrots.com</code> is perfectly okay,
    129129                although it too must be capable of being resolved via DNS, something that functions correctly
    130130                if Windows 200x ADS has been properly installed and configured.
    131                 </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619723"></a>Routed Networks</h4></div></div></div><p>
    132                 <a class="indexterm" name="id2619731"></a>
    133                 <a class="indexterm" name="id2619738"></a>
    134                 <a class="indexterm" name="id2619747"></a>
     131                </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619760"></a>Routed Networks</h4></div></div></div><p>
     132                <a class="indexterm" name="id2619768"></a>
     133                <a class="indexterm" name="id2619775"></a>
     134                <a class="indexterm" name="id2619784"></a>
    135135                NetBIOS networks (Windows networking with NetBIOS over TCP/IP enabled) makes extensive use
    136136                of UDP-based broadcast traffic, as you saw during the exercises in <a class="link" href="primer.html" title="Chapter 16. Networking Primer">&#8220;Networking Primer&#8221;</a>.
    137137                </p><p>
    138                 <a class="indexterm" name="id2619767"></a>
    139                 <a class="indexterm" name="id2619774"></a>
    140                 <a class="indexterm" name="id2619780"></a>
     138                <a class="indexterm" name="id2619804"></a>
     139                <a class="indexterm" name="id2619811"></a>
     140                <a class="indexterm" name="id2619818"></a>
    141141                UDP broadcast traffic is not forwarded by routers. This means that NetBIOS broadcast-based
    142142                networking cannot function across routed networks (i.e., multi-subnet networks) unless
    143143                special provisions are made:
    144144                </p><div class="itemizedlist"><ul type="disc"><li><p>
    145                         <a class="indexterm" name="id2619797"></a>
    146                         <a class="indexterm" name="id2619804"></a>
    147                         <a class="indexterm" name="id2619811"></a>
     145                        <a class="indexterm" name="id2619835"></a>
     146                        <a class="indexterm" name="id2619841"></a>
     147                        <a class="indexterm" name="id2619848"></a>
    148148                        Either install on every Windows client an LMHOSTS file (located in the directory
    149149                        <code class="filename">C:\windows\system32\drivers\etc</code>). It is also necessary to
    … …  
    152152                        manual page for the <code class="filename">smb.conf</code> file.
    153153                        </p></li><li><p>
    154                         <a class="indexterm" name="id2619857"></a>
     154                        <a class="indexterm" name="id2619894"></a>
    155155                        Or configure Samba as a WINS server, and configure all network clients to use that
    156156                        WINS server in their TCP/IP configuration.
    157157                        </p></li></ul></div><div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"><h3 class="title">Note</h3><p>
    158                 <a class="indexterm" name="id2619874"></a>
    159                 <a class="indexterm" name="id2619883"></a>
     158                <a class="indexterm" name="id2619911"></a>
     159                <a class="indexterm" name="id2619920"></a>
    160160                The use of DNS is not an acceptable substitute for WINS. DNS does not store specific
    161161                information regarding NetBIOS networking particulars that get stored in the WINS
    162162                name resolution database and that Windows clients require and depend on.
    163                 </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619896"></a>Network Collisions</h4></div></div></div><p>
    164                 <a class="indexterm" name="id2619904"></a>
    165                 <a class="indexterm" name="id2619913"></a>
    166                 <a class="indexterm" name="id2619922"></a>
    167                 <a class="indexterm" name="id2619929"></a>
     163                </p></div></div><div class="sect3" lang="en"><div class="titlepage"><div><div><h4 class="title"><a name="id2619933"></a>Network Collisions</h4></div></div></div><p>
     164                <a class="indexterm" name="id2619941"></a>
     165                <a class="indexterm" name="id2619950"></a>
     166                <a class="indexterm" name="id2619959"></a>
     167                <a class="indexterm" name="id2619966"></a>
    168168                Excessive network activity causes NetBIOS network timeouts. Timeouts may result in
    169169                blue screen of death (BSOD) experiences. High collision rates may be caused by excessive
    … …  
    174174                in <a class="link" href="primer.html" title="Chapter 16. Networking Primer">&#8220;Networking Primer&#8221;</a>.
    175175                </p><p>
    176                 <a class="indexterm" name="id2619958"></a>
    177                 <a class="indexterm" name="id2619965"></a>
    178                 <a class="indexterm" name="id2619972"></a>
     176                <a class="indexterm" name="id2619995"></a>
     177                <a class="indexterm" name="id2620002"></a>
     178                <a class="indexterm" name="id2620009"></a>
    179179                Under no circumstances should the facility be supported by many routers, known as <code class="constant">NetBIOS
    180180                forwarding</code>, unless you know exactly what you are doing. Inappropriate use of this
    … …  
    184184                less than 15 KB/sec. After the NetBIOS forwarding was turned off, file transfer performance
    185185                immediately returned to 11 MB/sec.
    186                 </p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2619995"></a>Samba Configuration</h3></div></div></div><p>
     186                </p></div></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620033"></a>Samba Configuration</h3></div></div></div><p>
    187187        As a general rule, the contents of the <code class="filename">smb.conf</code> file should be kept as simple as possible.
    188188        No parameter should be specified unless you know it is essential to operation.
    189189        </p><p>
    190         <a class="indexterm" name="id2620015"></a>
    191         <a class="indexterm" name="id2620022"></a>
    192         <a class="indexterm" name="id2620029"></a>
     190        <a class="indexterm" name="id2620052"></a>
     191        <a class="indexterm" name="id2620060"></a>
     192        <a class="indexterm" name="id2620066"></a>
    193193        Many UNIX administrators like to fully document the settings in the <code class="filename">smb.conf</code> file. This is a
    194194        bad idea because it adds content to the file. The <code class="filename">smb.conf</code> file is re-read by every <code class="literal">smbd</code>
    … …  
    198198        It is recommended to keep a fully documented <code class="filename">smb.conf</code> file on hand, and then to operate Samba only
    199199        with an optimized file.
    200         </p><p><a class="indexterm" name="id2620079"></a>
     200        </p><p><a class="indexterm" name="id2620116"></a>
    201201        The preferred way to maintain a documented file is to call it something like <code class="filename">smb.conf.master</code>.
    202202        You can generate the optimized file by executing:
    … …  
    224224Press enter to see a dump of your service definitions
    225225</pre><p>
    226         <a class="indexterm" name="id2620138"></a>
     226        <a class="indexterm" name="id2620176"></a>
    227227        You now, of course, press the enter key to complete the command, or else abort it by pressing Ctrl-C.
    228228        The important thing to note is the noted Server role, as well as warning messages. Noted configuration
    … …  
    234234</pre><p>
    235235        </p><p>
    236         <a class="indexterm" name="id2620166"></a>
    237         <a class="indexterm" name="id2620173"></a>
    238         <a class="indexterm" name="id2620180"></a>
     236        <a class="indexterm" name="id2620203"></a>
     237        <a class="indexterm" name="id2620210"></a>
     238        <a class="indexterm" name="id2620217"></a>
    239239        There are two parameters that can cause severe network performance degradation: <em class="parameter"><code>socket options</code></em>
    240240        and <em class="parameter"><code>socket address</code></em>. The <em class="parameter"><code>socket options</code></em> parameter was often necessary
    … …  
    242242        this parameter being set. Do not use either parameter unless it has been proven necessary to use them.
    243243        </p><p>
    244         <a class="indexterm" name="id2620214"></a>
    245         <a class="indexterm" name="id2620221"></a>
    246         <a class="indexterm" name="id2620228"></a>
    247         <a class="indexterm" name="id2620235"></a>
     244        <a class="indexterm" name="id2620251"></a>
     245        <a class="indexterm" name="id2620258"></a>
     246        <a class="indexterm" name="id2620265"></a>
     247        <a class="indexterm" name="id2620272"></a>
    248248        Another <code class="filename">smb.conf</code> parameter that may cause severe network performance degradation is the
    249249        <em class="parameter"><code>strict sync</code></em> parameter. Do not use this at all. There is no good reason
    … …  
    252252        degrade network performance, so do not set it; if you must, do so with caution.
    253253        </p><p>
    254         <a class="indexterm" name="id2620276"></a>
    255         <a class="indexterm" name="id2620283"></a>
    256         <a class="indexterm" name="id2620290"></a>
    257         <a class="indexterm" name="id2620297"></a>
     254        <a class="indexterm" name="id2620313"></a>
     255        <a class="indexterm" name="id2620320"></a>
     256        <a class="indexterm" name="id2620327"></a>
     257        <a class="indexterm" name="id2620334"></a>
    258258        Finally, many network administrators deliberately disable opportunistic locking support. While this
    259259        does not degrade Samba performance, it significantly degrades Windows client performance because
    … …  
    263263        oplock support for operations that are tolerant of it. See <a class="link" href="appendix.html#ch12dblck" title="Shared Data Integrity">&#8220;Shared Data Integrity&#8221;</a> for more
    264264        information.
    265         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620323"></a>Use and Location of BDCs</h3></div></div></div><p>
    266         <a class="indexterm" name="id2620331"></a>
    267         <a class="indexterm" name="id2620337"></a>
    268         <a class="indexterm" name="id2620344"></a>
    269         <a class="indexterm" name="id2620351"></a>
    270         <a class="indexterm" name="id2620358"></a>
     265        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620360"></a>Use and Location of BDCs</h3></div></div></div><p>
     266        <a class="indexterm" name="id2620368"></a>
     267        <a class="indexterm" name="id2620374"></a>
     268        <a class="indexterm" name="id2620381"></a>
     269        <a class="indexterm" name="id2620388"></a>
     270        <a class="indexterm" name="id2620395"></a>
    271271        On a network segment where there is a PDC and a BDC, the BDC carries the bulk of the network logon
    272272        processing. If the BDC is a heavily loaded server, the PDC carries a greater proportion of
    … …  
    276276        and is undesirable.
    277277        </p><p>
    278         <a class="indexterm" name="id2620376"></a>
    279         <a class="indexterm" name="id2620383"></a>
     278        <a class="indexterm" name="id2620413"></a>
     279        <a class="indexterm" name="id2620420"></a>
    280280        As a general guide, instead of adding domain member servers to a network, you would be better advised
    281281        to add BDCs until there are fewer than 30 Windows clients per BDC. Beyond that ratio, you should add
    282282        domain member servers. This practice ensures that there are always sufficient domain controllers
    283283        to handle logon requests and authentication traffic.
    284         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620398"></a>Use One Consistent Version of MS Windows Client</h3></div></div></div><p>
     284        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620435"></a>Use One Consistent Version of MS Windows Client</h3></div></div></div><p>
    285285        Every network client has its own peculiarities. From a management perspective, it is easier to deal
    286286        with one version of MS Windows that is maintained to a consistent update level than it is to deal
    … …  
    290290        have necessitated special handling from the Samba server end. If you want to remain sane, keep you
    291291        client workstation configurations consistent.
    292         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620420"></a>For Scalability, Use SAN-Based Storage on Samba Servers</h3></div></div></div><p>
    293         <a class="indexterm" name="id2620429"></a>
    294         <a class="indexterm" name="id2620436"></a>
     292        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620457"></a>For Scalability, Use SAN-Based Storage on Samba Servers</h3></div></div></div><p>
     293        <a class="indexterm" name="id2620466"></a>
     294        <a class="indexterm" name="id2620473"></a>
    295295        Many SAN-based storage systems permit more than one server to share a common data store.
    296296        Use of a shared SAN data store means that you do not need to use time- and resource-hungry data
    297297        synchronization techniques.
    298298        </p><p>
    299         <a class="indexterm" name="id2620450"></a>
    300         <a class="indexterm" name="id2620456"></a>
     299        <a class="indexterm" name="id2620487"></a>
     300        <a class="indexterm" name="id2620494"></a>
    301301        The use of a collection of relatively low-cost front-end Samba servers that are coupled to
    302302        a shared backend SAN data store permits load distribution while containing costs below that
    303303        of installing and managing a complex clustering facility.
    304         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620470"></a>Distribute Network Load with MSDFS</h3></div></div></div><p>
    305         <a class="indexterm" name="id2620478"></a>
    306         <a class="indexterm" name="id2620485"></a>
     304        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620507"></a>Distribute Network Load with MSDFS</h3></div></div></div><p>
     305        <a class="indexterm" name="id2620515"></a>
     306        <a class="indexterm" name="id2620522"></a>
    307307        Microsoft DFS (distributed file system) technology has been implemented in Samba. MSDFS permits
    308308        data to be accessed from a single share and yet to actually be distributed across multiple actual
    … …  
    310310        implementation of an MSDFS installation.
    311311        </p><p>
    312         <a class="indexterm" name="id2620503"></a>
    313         <a class="indexterm" name="id2620512"></a>
     312        <a class="indexterm" name="id2620540"></a>
     313        <a class="indexterm" name="id2620550"></a>
    314314        The combination of multiple backend servers together with a front-end server and use of MSDFS
    315315        can achieve almost the same as you would obtain with a clustered Samba server.
    316         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620524"></a>Replicate Data to Conserve Peak-Demand Wide-Area Bandwidth</h3></div></div></div><p>
    317         <a class="indexterm" name="id2620533"></a>
    318         <a class="indexterm" name="id2620540"></a>
    319         <a class="indexterm" name="id2620547"></a>
     316        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620562"></a>Replicate Data to Conserve Peak-Demand Wide-Area Bandwidth</h3></div></div></div><p>
     317        <a class="indexterm" name="id2620570"></a>
     318        <a class="indexterm" name="id2620577"></a>
     319        <a class="indexterm" name="id2620584"></a>
    320320        Consider using <code class="literal">rsync</code> to replicate data across the WAN during times
    321321        of low utilization. Users can then access the replicated data store rather than needing to do so
    … …  
    324324        implementation if you choose to permit modification and return replication of the modified file;
    325325        otherwise, you may inadvertently overwrite important data.
    326         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620570"></a>Hardware Problems</h3></div></div></div><p>
    327         <a class="indexterm" name="id2620578"></a>
    328         <a class="indexterm" name="id2620585"></a>
    329         <a class="indexterm" name="id2620592"></a>
    330         <a class="indexterm" name="id2620599"></a>
    331         <a class="indexterm" name="id2620608"></a>
    332         <a class="indexterm" name="id2620617"></a>
     326        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620607"></a>Hardware Problems</h3></div></div></div><p>
     327        <a class="indexterm" name="id2620615"></a>
     328        <a class="indexterm" name="id2620622"></a>
     329        <a class="indexterm" name="id2620629"></a>
     330        <a class="indexterm" name="id2620636"></a>
     331        <a class="indexterm" name="id2620645"></a>
     332        <a class="indexterm" name="id2620654"></a>
    333333        Networking hardware prices have fallen sharply over the past 5 years. A surprising number
    334334        of Samba networking problems over this time have been traced to defective network interface
    335335        cards (NICs) or defective HUBs, switches, and cables.
    336336        </p><p>
    337         <a class="indexterm" name="id2620634"></a>
     337        <a class="indexterm" name="id2620671"></a>
    338338        Not surprising is the fact that network administrators do not like to be shown to have made
    339339        a bad decision. Money saved in buying low-cost hardware may result in high costs incurred
    340340        in corrective action.
    341341        </p><p>
    342         <a class="indexterm" name="id2620647"></a>
    343         <a class="indexterm" name="id2620654"></a>
    344         <a class="indexterm" name="id2620661"></a>
    345         <a class="indexterm" name="id2620668"></a>
    346         <a class="indexterm" name="id2620675"></a>
     342        <a class="indexterm" name="id2620684"></a>
     343        <a class="indexterm" name="id2620691"></a>
     344        <a class="indexterm" name="id2620698"></a>
     345        <a class="indexterm" name="id2620705"></a>
     346        <a class="indexterm" name="id2620712"></a>
    347347        Defective NICs, HUBs, and switches may appear as intermittent network access problems, intermittent
    348348        or persistent data corruption, slow network throughput, low performance, or even as BSOD
    … …  
    353353        Defective hardware problems may take patience and persistence before the real cause can be discovered.
    354354        </p><p>
    355         <a class="indexterm" name="id2620698"></a>
     355        <a class="indexterm" name="id2620736"></a>
    356356        Networking hardware defects can significantly impact perceived Samba performance, but defective
    357357        RAID controllers as well as SCSI and IDE hard disk controllers have also been known to impair Samba server
    … …  
    360360        administrator until the entire server was replaced. While you may well think that this would never
    361361        happen to you, experience shows that given the right (unfortunate) circumstances, this can happen to anyone.
    362         </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620728"></a>Large Directories</h3></div></div></div><p>
     362        </p></div><div class="sect2" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="id2620755"></a>Large Directories</h3></div></div></div><p>
    363363        There exist applications that create or manage directories containing many thousands of files. Such
    364364        applications typically generate many small files (less than 100 KB). At the best of times, under UNIX,
    … …  
    400400        as specified in the <code class="filename">smb.conf</code> stanza. This means that smbd will not be able to find lower case
    401401        filenames with these settings.  Note, this is done on a per-share basis.
    402         </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2620832"></a>Key Points Learned</h2></div></div></div><p>
     402        </p></div></div><div class="sect1" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2620859"></a>Key Points Learned</h2></div></div></div><p>
    403403        This chapter has touched in broad sweeps on a number of simple steps that can be taken
    404404        to ensure that your Samba network is resilient, scalable, and reliable, and that it
    … …  
    409409        her an even break.
    410410        </p><p>
    411         <a class="indexterm" name="id2620853"></a>
     411        <a class="indexterm" name="id2620880"></a>
    412412        Last, but not least, you should not only keep the network design simple, but also be sure it is
    413413        well documented. This book may serve as your pattern for documenting every
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