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diff --git a/docs-xml/Samba3-HOWTO/TOSHARG-VFS.xml b/docs-xml/Samba3-HOWTO/TOSHARG-VFS.xml new file mode 100644 index 0000000000..b8bd3277a6 --- /dev/null +++ b/docs-xml/Samba3-HOWTO/TOSHARG-VFS.xml @@ -0,0 +1,949 @@ +<?xml version="1.0" encoding="iso-8859-1"?> +<!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc"> +<chapter id="VFS"> +<chapterinfo> + &author.jelmer; + &author.jht; + &author.tpot; + <author><firstname>Simo</firstname><surname>Sorce</surname><contrib>original vfs_skel README</contrib></author> + <author><firstname>Alexander</firstname><surname>Bokovoy</surname><contrib>original vfs_netatalk docs</contrib></author> + <author><firstname>Stefan</firstname><surname>Metzmacher</surname><contrib>Update for multiple modules</contrib></author> + <author><firstname>Ed</firstname><surname>Riddle</surname><contrib>original shadow_copy docs</contrib></author> +</chapterinfo> +<title>Stackable VFS modules</title> + +<sect1> +<title>Features and Benefits</title> + +<para> +<indexterm><primary>Virtual File System</primary><see>VFS</see></indexterm> +<indexterm><primary>modules</primary></indexterm> +<indexterm><primary>loaded modules</primary></indexterm> +Stackable VFS (Virtual File System) modules support was new to Samba-3 and has proven quite popular. Samba +passes each request to access the UNIX file system through the loaded VFS modules. This chapter covers the +modules that come with the Samba source and provides references to some external modules. +</para> + + +</sect1> + +<sect1> +<title>Discussion</title> + +<para> +<indexterm><primary>IRIX</primary></indexterm> +<indexterm><primary>GNU/Linux</primary></indexterm> +If not supplied with your platform distribution binary Samba package, you may have problems compiling these +modules, as shared libraries are compiled and linked in different ways on different systems. They currently +have been tested against GNU/Linux and IRIX. +</para> + +<para> +<indexterm><primary>VFS modules</primary></indexterm> +<indexterm><primary>modules</primary></indexterm> +<indexterm><primary>recycle bin</primary></indexterm> +To use the VFS modules, create a share similar to the one below. The important parameter is the <smbconfoption +name="vfs objects"/> parameter where you can list one or more VFS modules by name. For example, to log all +access to files and put deleted files in a recycle bin, see <link linkend="vfsrecyc">the smb.conf with VFS +modules example</link>: +</para> + +<example id="vfsrecyc"> +<title>smb.conf with VFS modules</title> +<smbconfblock> +<smbconfsection name="[audit]"/> +<smbconfoption name="comment">Audited /data directory</smbconfoption> +<smbconfoption name="path">/data</smbconfoption> +<smbconfoption name="vfs objects">audit recycle</smbconfoption> +<smbconfoption name="writeable">yes</smbconfoption> +<smbconfoption name="browseable">yes</smbconfoption> +</smbconfblock> +</example> + +<para> +<indexterm><primary>virus scanner</primary></indexterm> +<indexterm><primary>scanner module</primary></indexterm> +<indexterm><primary>recycle bin</primary></indexterm> +The modules are used in the order in which they are specified. Let's say that you want to both have a virus +scanner module and a recycle bin module. It is wise to put the virus scanner module as the first one so that +it is the first to get run and may detect a virus immediately, before any action is performed on that file. +<smbconfoption name="vfs objects">vscan-clamav recycle</smbconfoption> +</para> + +<para> +<indexterm><primary>/usr/local/samba/lib/vfs</primary></indexterm> +<indexterm><primary>/usr/lib/samba/vfs</primary></indexterm> +Samba will attempt to load modules from the <filename>/lib</filename> directory in the root directory of the +Samba installation (usually <filename>/usr/lib/samba/vfs</filename> or +<filename>/usr/local/samba/lib/vfs</filename>). +</para> + +<para> +<indexterm><primary>modules</primary></indexterm> +<indexterm><primary>VFS</primary></indexterm> +<indexterm><primary>multiple modules</primary></indexterm> +<indexterm><primary>multiple VFS</primary></indexterm> +Some modules can be used twice for the same share. This can be done using a configuration similar to the one +shown in <link linkend="multimodule">the smb.conf with multiple VFS modules</link>. + +<example id="multimodule"> +<title>smb.conf with multiple VFS modules</title> +<smbconfblock> +<smbconfsection name="[test]"/> +<smbconfoption name="comment">VFS TEST</smbconfoption> +<smbconfoption name="path">/data</smbconfoption> +<smbconfoption name="writeable">yes</smbconfoption> +<smbconfoption name="browseable">yes</smbconfoption> +<smbconfoption name="vfs objects">example:example1 example example:test</smbconfoption> +<smbconfoption name="example1: parameter">1</smbconfoption> +<smbconfoption name="example: parameter">5</smbconfoption> +<smbconfoption name="test: parameter">7</smbconfoption> +</smbconfblock> +</example> +</para> + +</sect1> + +<sect1> +<title>Included Modules</title> + + <sect2> + <title>audit</title> + + <para> +<indexterm><primary>audit file access</primary></indexterm> + A simple module to audit file access to the syslog facility. The following operations are logged: + <itemizedlist> + <listitem><para>share</para></listitem> + <listitem><para>connect/disconnect</para></listitem> + <listitem><para>directory opens/create/remove</para></listitem> + <listitem><para>file open/close/rename/unlink/chmod</para></listitem> + </itemizedlist> + </para> + + </sect2> + + <sect2> + <title>default_quota</title> + + <para> + This module allows the default quota values, in the windows explorer GUI, to be stored on a Samba-3 server. + The challenge is that linux filesystems only store quotas for users and groups, but no default quotas. + </para> + + <para> + Samba returns NO_LIMIT as the default quotas by default and refuses to update them. With this module you + can store the default quotas that are reported to a windows client, in the quota record of a user. By + default the root user is taken because quota limits for root are typically not enforced. + </para> + + <para> + This module takes 2 parametric entries in the &smb.conf; file. The default prefix for each is the + <quote>default_quota</quote>. This can be overwrittem when you load the module in the <emphasis>vfs + modules</emphasis> parameter like this: +<screen> +vfs objects = default_quota:myprefix +</screen> + </para> + + <para> + The parametric entries that may be specified for the default_quotas module are: + </para> + + <variablelist> + <varlistentry> + <term>myprefix:uid</term> + <listitem><para> + This parameter takes a integer argument that specifies the uid of the quota record that will be + used for storing the default user quotas. + </para> + + <para> + The default value is 0 (for root user). An example of use is: +<screen> +vfs objects = default_quota +default_quota: uid = 65534 +</screen> + The above demonstrates the case where the <constant>myprefix</constant> was omitted, thus the + default prefix is the name of the module. When a <constant>myprefix</constant> parameter is + specified the above can be re-written like this: +<screen> +vfs objects = default_quota:myprefix +myprefix: uid = 65534 +</screen> + </para></listitem> + </varlistentry> + + <varlistentry> + <term>myprefix:uid nolimit</term> + <listitem><para> + This parameter takes a boolean argument that specifies if the stored default quota values also be + reported for the user record, or if the value <constant>NO_LIMIT</constant> should be reported to + the windows client for the user specified by the <parameter>prefix:uid</parameter> parameter. + </para> + + <para> + The default value is <constant>yes</constant> (which means to report NO_LIMIT). An example of use + is shown here: +<screen> +vfs objects = default_quota:myprefix +myprefix: uid nolimit = no +</screen> + </para></listitem> + </varlistentry> + + <varlistentry> + <term>myprefix:gid</term> + <listitem><para> + This parameter takes an integer argument, it's just like the <parameter>prefix>:uid</parameter> but + for group quotas. NOTE: group quotas are not supported from the windows explorer. + </para> + + <para> + The default value is 0 (for root group). An example of use is shown here: +<screen> +vfs objects = default_quota +default_quota: gid = 65534 +</screen> + </para></listitem> + </varlistentry> + + <varlistentry> + <term>myprefix:gid nolimit</term> + <listitem><para> + This parameter takes a boolean argument, just like the <parameter>prefix>:uid nolimit</parameter> + but for group quotas. NOTE: group quotas are not supported from the windows explorer. + </para> + + <para> + The default value is <constant>yes</constant> (which means to report NO_LIMIT). An example of use + is shown here: +<screen> +vfs objects = default_quota +default_quota: uid nolimit = no +</screen> + </para></listitem> + </varlistentry> + </variablelist> + + <para> + An example of use of multiple parametric specifications is shown here: +<screen> +... +vfs objects = default_quota:quotasettings +quotasettings: uid nolimit = no +quotasettings: gid = 65534 +quotasettings: gid nolimit = no +... +</screen> + </para> + + </sect2> + + <sect2> + <title>extd_audit</title> + + <para> +<indexterm><primary>audit module</primary></indexterm> +<indexterm><primary>extd_audit module</primary></indexterm> +<indexterm><primary>smbd</primary></indexterm> + This module is identical with the <command>audit</command> module above except + that it sends audit logs to both syslog as well as the <command>smbd</command> log files. The + <smbconfoption name="log level"/> for this module is set in the &smb.conf; file. + </para> + + <para> + Valid settings and the information that will be recorded are shown in <link linkend="xtdaudit">the next table</link>. + </para> + + <table frame="all" id="xtdaudit"> + <title>Extended Auditing Log Information</title> + <tgroup cols="2" align="center"> + <thead> + <row><entry align="center">Log Level</entry><entry>Log Details - File and Directory Operations</entry></row> + </thead> + <tbody> + <row><entry align="center">0</entry><entry align="left">Make Directory, Remove Directory, Unlink</entry></row> + <row><entry align="center">1</entry><entry align="left">Open Directory, Rename File, Change Permissions/ACLs</entry></row> + <row><entry align="center">2</entry><entry align="left">Open & Close File</entry></row> + <row><entry align="center">10</entry><entry align="left">Maximum Debug Level</entry></row> + </tbody> + </tgroup> + </table> + + <sect3> + <title>Configuration of Auditing</title> + + <para> +<indexterm><primary>logging</primary></indexterm> + This auditing tool is more felxible than most people readily will recognize. There are a number of ways + by which useful logging information can be recorded. + </para> + + <itemizedlist> + <listitem><para>Syslog can be used to record all transaction. This can be disabled by setting + in the &smb.conf; file <parameter>syslog = 0</parameter>.</para></listitem> + <listitem><para>Logging can take place to the default log file (<filename>log.smbd</filename>) + for all loaded VFS modules just by setting in the &smb.conf; file + <parameter>log level = 0 vfs:x</parameter>, where x is the log level. + This will disable general logging while activating all logging of VFS + module activity at the log level specified.</para></listitem> + <listitem><para>Detailed logging can be obtained per user, per client machine, etc. + This requires the above together with the creative use of the + <parameter>log file</parameter> settings.</para> + <para>An example of detailed per-user and per-machine logging can + be obtained by setting + <smbconfoption name="log file">/var/log/samba/%U.%m.log</smbconfoption>. + </para></listitem> + </itemizedlist> + + <para> + Auditing information often must be preserved for a long time. So that the log files do not get rotated + it is essential that the <smbconfoption name="max log size">0</smbconfoption> be set + in the &smb.conf; file. + </para> + + </sect3> + + </sect2> + + <sect2 id="fakeperms"> + <title>fake_perms</title> + + <para> +<indexterm><primary>fake_perms</primary></indexterm> +<indexterm><primary>Roaming Profile</primary></indexterm> +<indexterm><primary>writeable</primary></indexterm> +<indexterm><primary>read only</primary></indexterm> + This module was created to allow Roaming Profile files and directories to be set (on the Samba server + under UNIX) as read only. This module will, if installed on the Profiles share, report to the client + that the Profile files and directories are writeable. This satisfies the client even though the files + will never be overwritten as the client logs out or shuts down. + </para> + + </sect2> + + <sect2> + <title>recycle</title> + + <para> +<indexterm><primary>recycle</primary></indexterm> +<indexterm><primary>unlink calls</primary></indexterm> +<indexterm><primary>recycle directory</primary></indexterm> + A Recycle Bin-like module. Where used, unlink calls will be intercepted and files moved + to the recycle directory instead of being deleted. This gives the same effect as the + <guiicon>Recycle Bin</guiicon> on Windows computers. + </para> + + <para> +<indexterm><primary>recycle</primary></indexterm> +<indexterm><primary>.recycle</primary></indexterm> +<indexterm><primary>recycle:keeptree</primary></indexterm> +<indexterm><primary>deleted files</primary></indexterm> + The <guiicon>Recycle Bin</guiicon> will not appear in + <application>Windows Explorer</application> views of the network + file system (share) nor on any mapped drive. Instead, a directory + called <filename>.recycle</filename> will be automatically created + when the first file is deleted and <parameter>recycle:repository</parameter> + is not configured. + If <parameter>recycle:repository</parameter> is configured, the name + of the created directory depends on <parameter>recycle:repository</parameter>. + Users can recover files from the recycle bin. If the + <parameter>recycle:keeptree</parameter> has been specified, deleted + files will be found in a path identical with that from which the + file was deleted. + </para> + + <para>Supported options for the <command>recycle</command> module are as follow: + <variablelist> + <varlistentry> + <term>recycle:repository</term> + <listitem><para> +<indexterm><primary>recycle:repository</primary></indexterm> + Path of the directory where deleted files should be moved. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:directory_mode</term> + <listitem><para> +<indexterm><primary>directory_mode</primary></indexterm> + Set it to the octal mode you want for the recycle directory. With + this mode the recycle directory will be created if it not + exists and the first file is deleted. + If <parameter>recycle:subdir_mode</parameter> is not set, these + mode also apply to sub directories. + If <parameter>directory_mode</parameter> not exists, the default + mode 0700 is used. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:subdir_mode</term> + <listitem><para> +<indexterm><primary>recycle:subdir_mode</primary></indexterm> + Set it to the octal mode you want for the sub directories of + the recycle directory. With this mode the sub directories will + be created. + If <parameter>recycle:subdir_mode</parameter> is not set, the + sub directories will be created with the mode from + <parameter>directory_mode</parameter>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:keeptree</term> + <listitem><para> +<indexterm><primary>recycle:keeptree</primary></indexterm> + Specifies whether the directory structure should be kept or if the files in the directory that is being + deleted should be kept separately in the recycle bin. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:versions</term> + <listitem><para> +<indexterm><primary>recycle:versions</primary></indexterm> + If this option is set, two files + with the same name that are deleted will both + be kept in the recycle bin. Newer deleted versions + of a file will be called <quote>Copy #x of <replaceable>filename</replaceable></quote>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:touch</term> + <listitem><para> +<indexterm><primary>recycle:touch</primary></indexterm> + Specifies whether a file's access date should be touched when the file is moved to the recycle bin. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:touch_mtime</term> + <listitem><para> +<indexterm><primary>recycle:touch</primary></indexterm> + Specifies whether a file's last modify date date should be touched when the file is moved to the recycle bin. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:maxsize</term> + <listitem><para> +<indexterm><primary>recycle:maxsize</primary></indexterm> + Files that are larger than the number of bytes specified by this parameter will not be put into the recycle bin. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:exclude</term> + <listitem><para> +<indexterm><primary>recycle:exclude</primary></indexterm> + List of files that should not be put into the recycle bin when deleted, but deleted in the regular way. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:exclude_dir</term> + <listitem><para> +<indexterm><primary>recycle:exclude_dir</primary></indexterm> + Contains a list of directories. When files from these directories are + deleted, they are not put into the + recycle bin but are deleted in the + regular way. + </para></listitem> + </varlistentry> + + <varlistentry> + <term>recycle:noversions</term> + <listitem><para> +<indexterm><primary>recycle:noversions</primary></indexterm> + Specifies a list of paths (wildcards such as * and ? are supported) for which no versioning + should be used. Only useful when <emphasis>recycle:versions</emphasis> is enabled. + </para></listitem> + </varlistentry> + </variablelist> + </para> + + </sect2> + + <sect2> + <title>netatalk</title> + + <para> +<indexterm><primary>netatalk</primary></indexterm> + A netatalk module will ease co-existence of Samba and netatalk file sharing services. + </para> + + <para>Advantages compared to the old netatalk module: + <itemizedlist> +<indexterm><primary>.AppleDouble</primary></indexterm> + <listitem><para>Does not care about creating .AppleDouble forks, just keeps them in sync.</para></listitem> + <listitem><para>If a share in &smb.conf; does not contain .AppleDouble item in hide or veto list, it will be added automatically.</para></listitem> + </itemizedlist> + </para> + + </sect2> + + <sect2> + <title>shadow_copy</title> + + <warning><para> +<indexterm><primary>shadow_copy</primary></indexterm> + <emphasis>THIS IS NOT A BACKUP, ARCHIVAL, OR VERSION CONTROL SOLUTION!</emphasis> + </para> + + <para> +<indexterm><primary>version control</primary></indexterm> + With Samba or Windows servers, shadow_copy is designed to be an end-user tool only. It does not replace or + enhance your backup and archival solutions and should in no way be considered as such. Additionally, if you + need version control, implement a version control system. You have been warned. + </para></warning> + + + <para> + The shadow_copy module allows you to setup functionality that is similar to MS shadow copy services. When + setup properly, this module allows Microsoft shadow copy clients to browse "shadow copies" on Samba shares. + You will need to install the shadow copy client. You can get the MS shadow copy client <ulink noescape="1" + url="http://www.microsoft.com/windowsserver2003/downloads/shadowcopyclient.mspx">here.</ulink>. Note the + additional requirements for pre-Windows XP clients. I did not test this functionality with any pre-Windows XP + clients. You should be able to get more information about MS Shadow Copy <ulink noescape="1" + url="http://www.microsoft.com/windowsserver2003/techinfo/overview/scr.mspx">from the Microsoft's site</ulink>. + </para> + + <para> +<indexterm><primary>shadow_copy</primary></indexterm> +<indexterm><primary>VFS module</primary></indexterm> +<indexterm><primary>shadow_copy module</primary></indexterm> +<indexterm><primary>LVM</primary></indexterm> +<indexterm><primary>EVMS</primary></indexterm> +<indexterm><primary>Logical Volume Manager</primary><see>LVM</see></indexterm> + The shadow_copy VFS module requires some underlying file system setup with some sort of Logical Volume Manager + (LVM) such as LVM1, LVM2, or EVMS. Setting up LVM is beyond the scope of this document; however, we will + outline the steps we took to test this functionality for <emphasis>example purposes only.</emphasis> You need + to make sure the LVM implementation you choose to deploy is ready for production. Make sure you do plenty of + tests. + </para> + + <para> + Here are some common resources for LVM and EVMS: + </para> + + <itemizedlist> + <listitem> + <para><ulink noescape="1" + url="http://www.sistina.com/products_lvm_download.htm">Sistina's + LVM1 and LVM2</ulink></para> + </listitem> + <listitem> + <para><ulink url="http://evms.sourceforge.net/">Enterprise Volume Management System (EVMS)</ulink></para> + </listitem> + <listitem> + <para><ulink url="http://tldp.org/HOWTO/LVM-HOWTO/">The LVM HOWTO</ulink></para> + </listitem> + <listitem> + <para> + See <ulink url="http://www-106.ibm.com/developerworks/linux/library/l-lvm/">Learning + Linux LVM, Part 1</ulink> and <ulink url="http://www-106.ibm.com/developerworks/library/l-lvm2.html">Learning + Linux LWM, Part 2</ulink> for Daniel Robbins' well-written, two part tutorial on Linux and LVM using LVM + source code and reiserfs.</para> + </listitem> + </itemizedlist> + + <sect3> + <title>Shadow Copy Setup</title> + <para> +<indexterm><primary>XFS file system</primary></indexterm> +<indexterm><primary>Debian Sarge</primary></indexterm> + At the time of this writing, not much testing has been done. I tested the shadow copy VFS module with a + specific scenario which was not deployed in a production environment, but more as a proof of concept. The + scenario involved a Samba-3 file server on Debian Sarge with an XFS file system and LVM1. I do NOT recommend + you use this as a solution without doing your own due diligence with regard to all the components presented + here. That said, following is an basic outline of how I got things going. + </para> + + <orderedlist> + <listitem> + <formalpara><title>Installed Operating System </title> + <para> + In my tests, I used <ulink url="http://www.debian.org/devel/debian-installer/">Debian + Sarge</ulink> (i.e., testing) on an XFS file system. Setting up the OS is a bit beyond the scope of this + document. It is assumed that you have a working OS capable of running Samba. + </para></formalpara> + </listitem> + + <listitem> + <formalpara><title>Install & Configure Samba</title> + <para> + See the <link linkend="introduction">installation section</link> of this HOWTO for more detail on this. + It doesn't matter if it is a Domain Controller or Member File Server, but it is assumed that you have a + working Samba 3.0.3 or later server running. + </para></formalpara> + </listitem> + + <listitem> + <formalpara><title>Install & Configure LVM</title> + <para> +<indexterm><primary>shadow copies</primary></indexterm> +<indexterm><primary>Snapshots</primary></indexterm> + Before you can make shadow copies available to the client, you have to create the shadow copies. This is + done by taking some sort of file system snapshot. Snapshots are a typical feature of Logical Volume + Managers such as LVM, so we first need to have that setup. + </para></formalpara> + + <itemizedlist> + <para> + The following is provided as an example and will be most helpful for Debian users. Again, this was tested + using the "testing" or "Sarge" distribution. + </para> + + <listitem> + <para> +<indexterm><primary>lvm10 package</primary></indexterm> +<indexterm><primary>devfsd package</primary></indexterm> +<indexterm><primary>Debian</primary></indexterm> +<indexterm><primary>xfsprogs</primary></indexterm> +<indexterm><primary>apt-get</primary></indexterm> + Install lvm10 and devfsd packages if you have not done so already. On Debian systems, you are warned of the + interaction of devfs and lvm1 which requires the use of devfs filenames. Running <command>apt-get update + && apt-get install lvm10 devfsd xfsprogs</command> should do the trick for this example. + </para></listitem> + + <listitem><para> +<indexterm><primary>create volume</primary></indexterm> +<indexterm><primary>create partition</primary></indexterm> +<indexterm><primary>fdisk</primary></indexterm> +<indexterm><primary>cfdisk</primary></indexterm> +<indexterm><primary>Linux LVM</primary></indexterm> + Now you need to create a volume. You will need to create a partition (or partitions) to add to your volume. + Use your favorite partitioning tool (e.g., Linux fdisk, cfdisk, etc.). The partition type should be set to + 0x8e for "Linux LVM." In this example, we will use /dev/hdb1. + </para> + + <para> +<indexterm><primary>Linux LVM partition</primary></indexterm> +<indexterm><primary>LVM volume</primary></indexterm> +<indexterm><primary>modprobe</primary></indexterm> + Once you have the Linux LVM partition (type 0x8e), you can run a series of commands to create the LVM volume. + You can use several disks and/or partitions, but we will use only one in this example. You may also need to + load the kernel module with something like <command>modprobe lvm-mod</command> and set your system up to load + it on reboot by adding it to (<filename>/etc/modules</filename>). + </para></listitem> + + <listitem><para> +<indexterm><primary>pvcreate</primary></indexterm> + Create the physical volume with <command>pvcreate /dev/hdb1</command> + </para></listitem> + + <listitem><para> +<indexterm><primary>vgcreate</primary></indexterm> +<indexterm><primary>volume group</primary></indexterm> + Create the volume group and add /dev/hda1 to it with <command>vgcreate shadowvol /dev/hdb1</command> + </para> + + <para> +<indexterm><primary>vgdisplay</primary></indexterm> + You can use <command>vgdisplay</command> to review information about the volume group. + </para></listitem> + + <listitem><para> +<indexterm><primary>lvcreate</primary></indexterm> + Now you can create the logical volume with something like <command>lvcreate -L400M -nsh_test shadowvol</command> + </para> + + <para> +<indexterm><primary>/dev/shadowvol</primary></indexterm> + This creates the logical volume of 400 MBs named "sh_test" in the volume group we created called shadowvol. + If everything is working so far, you should see them in <filename>/dev/shadowvol</filename>. + </para></listitem> + + <listitem><para> +<indexterm><primary>mkfs.xfs</primary></indexterm> + Now we should be ready to format the logical volume we named sh_test with <command>mkfs.xfs + /dev/shadowvol/sh_test</command> + </para> + + <para> +<indexterm><primary>logical volume</primary></indexterm> +<indexterm><primary>LVM</primary></indexterm> +<indexterm><primary>freezing</primary></indexterm> +<indexterm><primary>resizing</primary></indexterm> +<indexterm><primary>growing</primary></indexterm> + You can format the logical volume with any file system you choose, but make sure to use one that allows you to + take advantage of the additional features of LVM such as freezing, resizing, and growing your file systems. + </para> + + <para> +<indexterm><primary>LVM volume</primary></indexterm> +<indexterm><primary>shadow_copy</primary></indexterm> +<indexterm><primary>module</primary></indexterm> + Now we have an LVM volume where we can play with the shadow_copy VFS module. + </para></listitem> + + <listitem><para> +<indexterm><primary>mkdir</primary></indexterm> +<indexterm><primary>permissions</primary></indexterm> +<indexterm><primary>chmod</primary></indexterm> + Now we need to prepare the directory with something like +<screen> +&rootprompt; mkdir -p /data/shadow_share +</screen> + or whatever you want to name your shadow copy-enabled Samba share. Make sure you set the permissions so that + you can use it. If in doubt, use <command>chmod 777 /data/shadow_share</command> and tighten the permissions + once you get things working. + </para></listitem> + + <listitem><para> +<indexterm><primary>mount</primary></indexterm> + Mount the LVM volume using something like <command>mount /dev/shadowvol/sh_test /data/shadow_share</command> + </para> + + <para> +<indexterm><primary>/etc/fstab</primary></indexterm> + You may also want to edit your <filename>/etc/fstab</filename> so that this partition mounts during the system boot. + </para></listitem> + </itemizedlist> + + </listitem> + + <listitem> + <formalpara><title>Install & Configure the shadow_copy VFS Module</title> + <para> + Finally we get to the actual shadow_copy VFS module. The shadow_copy VFS module should be available in Samba + 3.0.3 and higher. The smb.conf configuration is pretty standard. Here is our example of a share configured + with the shadow_copy VFS module: + </para></formalpara> + + <example id="vfsshadow"> + <title>Share With shadow_copy VFS</title> + <smbconfblock> + <smbconfsection name="[shadow_share]"/> + <smbconfoption name="comment">Shadow Copy Enabled Share</smbconfoption> + <smbconfoption name="path">/data/shadow_share</smbconfoption> + <smbconfoption name="vfs objects">shadow_copy</smbconfoption> + <smbconfoption name="writeable">yes</smbconfoption> + <smbconfoption name="browseable">yes</smbconfoption> + </smbconfblock> + </example> + + </listitem> + + <listitem> + <formalpara><title>Create Snapshots and Make Them Available to shadow_copy.so</title> + <para> +<indexterm><primary>shadow_copy</primary></indexterm> +<indexterm><primary>LVM snapshots</primary></indexterm> +<indexterm><primary>module</primary></indexterm> + Before you can browse the shadow copies, you must create them and mount them. This will most likely be done + with a script that runs as a cron job. With this particular solution, the shadow_copy VFS module is used to + browse LVM snapshots. Those snapshots are not created by the module. They are not made available by the + module either. This module allows the shadow copy-enabled client to browse the snapshots you take and make + available. + </para></formalpara> + + <para> + Here is a simple script used to create and mount the snapshots: +<screen> +#!/bin/bash +# This is a test, this is only a test +SNAPNAME=`date +%Y.%m.%d-%H.%M.%S` +xfs_freeze -f /data/shadow_share/ +lvcreate -L10M -s -n $SNAPNAME /dev/shadowvol/sh_test +xfs_freeze -u /data/shadow_share/ +mkdir /data/shadow_share/@GMT-$SNAPNAME +mount /dev/shadowvol/$SNAPNAME \ + /data/shadow_share/@GMT-$SNAPNAME -onouuid,ro +</screen> + Note that the script does not handle other things like remounting snapshots on reboot. + </para></listitem> + + <listitem> + <formalpara><title>Test From Client</title> + <para> + To test, you will need to install the shadow copy client which you can obtain from the <ulink + url="http://www.microsoft.com/windowsserver2003/downloads/shadowcopyclient.mspx">Microsoft web site.</ulink> I + only tested this with an XP client so your results may vary with other pre-XP clients. Once installed, with + your XP client you can right-click on specific files or in the empty space of the shadow_share and view the + "properties." If anything has changed, then you will see it on the "Previous Versions" tab of the properties + window. + </para></formalpara> + </listitem> + </orderedlist> + + </sect3> +</sect2> + +</sect1> + +<sect1> +<title>VFS Modules Available Elsewhere</title> + +<para> +<indexterm><primary>VFS modules</primary></indexterm> +This section contains a listing of various other VFS modules that have been posted but do not currently reside +in the Samba CVS tree for one reason or another (e.g., it is easy for the maintainer to have his or her own +CVS tree). +</para> + +<para> +No statements about the stability or functionality of any module should be implied due to its presence here. +</para> + +<sect2> +<title>DatabaseFS</title> + +<para> +<indexterm><primary>DatabaseFS</primary></indexterm> +URL: <ulink noescape="1" url="http://www.css.tayloru.edu/~elorimer/databasefs/index.php"> +Taylors University DatabaeFS</ulink> +</para> + +<para>By <ulink url="mailto:elorimer@css.tayloru.edu">Eric Lorimer.</ulink></para> + +<para> +I have created a VFS module that implements a fairly complete read-only filesystem. It presents information +from a database as a filesystem in a modular and generic way to allow different databases to be used. +(Originally designed for organizing MP3s under directories such as <quote>Artists,</quote> <quote>Song +Keywords,</quote> and so on. I have since easily applied it to a student roster database.) The directory +structure is stored in the database itself and the module makes no assumptions about the database structure +beyond the table it requires to run. +</para> + +<para> +Any feedback would be appreciated: comments, suggestions, patches, and so on. If nothing else, it +might prove useful for someone else who wishes to create a virtual filesystem. +</para> + +</sect2> + +<sect2> +<title>vscan</title> + +<indexterm><primary>vscan</primary></indexterm> +<para>URL: <ulink noescape="1" url="http://www.openantivirus.org/projects.php#samba-vscan"> +Open Anti-Virus vscan</ulink> +</para> + +<para> +<indexterm><primary>samba-vscan</primary></indexterm> +samba-vscan is a proof-of-concept module for Samba, which provides on-access anti-virus support for files +shared using Samba. samba-vscan supports various virus scanners and is maintained by Rainer Link. +</para> + +</sect2> + +<sect2> +<title>vscan-clamav</title> +<para> +Samba users have been using the RPMS from SerNet without a problem. +OpenSUSE Linux users have also used the vscan scanner for quite some time +with excellent results. It does impact overall write performance though. +</para> + +<para> +The following share stanza is a good guide for those wanting to configure vscan-clamav: +</para> + +<screen> +[share] +vfs objects = vscan-clamav +vscan-clamav: config-file = /etc/samba/vscan-clamav.conf +</screen> + +<para> +The following example of the <filename>vscan-clamav.conf</filename> file may help to get this +fully operational: +</para> + +<screen> +<title>VFS: Vscan ClamAV Control File</title> +# +# /etc/samba/vscan-clamav.conf +# + +[samba-vscan] +; run-time configuration for vscan-samba using +; clamd +; all options are set to default values + +; do not scan files larger than X bytes. If set to 0 (default), +; this feature is disable (i.e. all files are scanned) +max file size = 10485760 + +; log all file access (yes/no). If set to yes, every access will +; be logged. If set to no (default), only access to infected files +; will be logged +verbose file logging = no + +; if set to yes (default), a file will be scanned while opening +scan on open = yes +; if set to yes, a file will be scanned while closing (default is yes) +scan on close = yes + +; if communication to clamd fails, should access to file denied? +; (default: yes) +deny access on error = no + +; if daemon failes with a minor error (corruption, etc.), +; should access to file denied? +; (default: yes) +deny access on minor error = no + +; send a warning message via Windows Messenger service +; when virus is found? +; (default: yes) +send warning message = yes + +; what to do with an infected file +; quarantine: try to move to quantine directory +; delete: delete infected file +; nothing: do nothing (default) +infected file action = quarantine + +; where to put infected files - you really want to change this! +quarantine directory = /opt/clamav/quarantine +; prefix for files in quarantine +quarantine prefix = vir- + +; as Windows tries to open a file multiple time in a (very) short time +; of period, samba-vscan use a last recently used file mechanism to avoid +; multiple scans of a file. This setting specified the maximum number of +; elements of the last recently used file list. (default: 100) +max lru files entries = 100 + +; an entry is invalidad after lru file entry lifetime (in seconds). +; (Default: 5) +lru file entry lifetime = 5 + +; exclude files from being scanned based on the MIME-type! Semi-colon +; seperated list (default: empty list). Use this with care! +exclude file types = + +; socket name of clamd (default: /var/run/clamd). Setting will be ignored if +; libclamav is used +clamd socket name = /tmp/clamd + +; limits, if vscan-clamav was build for using the clamav library (libclamav) +; instead of clamd + +; maximum number of files in archive (default: 1000) +libclamav max files in archive = 1000 + +; maximum archived file size, in bytes (default: 10 MB) +libclamav max archived file size = 5242880 + +; maximum recursion level (default: 5) +libclamav max recursion level = 5 +</screen> + +<para> +Obviously, a running clam daemon is necessary for this to work. This is a working example for me using ClamAV. +The ClamAV documentation should provide additional configuration examples. On your system these may be located +under the <filename>/usr/share/doc/</filename> directory. Some examples may also target other virus scanners, +any of which can be used. +</para> + +</sect2> +</sect1> + +</chapter> |