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| -rw-r--r-- | docs/howto/VFS.xml | 293 |
1 files changed, 289 insertions, 4 deletions
diff --git a/docs/howto/VFS.xml b/docs/howto/VFS.xml index 0399cf011b..5dec637cd6 100644 --- a/docs/howto/VFS.xml +++ b/docs/howto/VFS.xml @@ -6,6 +6,7 @@ <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> @@ -93,10 +94,10 @@ This can be done using a configuration similar to the one shown in <link linkend A simple module to audit file access to the syslog facility. The following operations are logged: <itemizedlist> - <listitem>share</listitem> - <listitem>connect/disconnect</listitem> - <listitem>directory opens/create/remove</listitem> - <listitem>file open/close/rename/unlink/chmod</listitem> + <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> @@ -245,6 +246,290 @@ This can be done using a configuration similar to the one shown in <link linkend </sect2> + <sect2> + <title>shadow_copy</title> + <warning> + <para> + <emphasis>THIS IS NOT A BACKUP, ARCHIVAL, OR VERSION CONTROL + SOLUTION!</emphasis></para> + <para> + 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> + 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: + <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 a two part tutorial on Linux and LVM using LVM + source code and reiserfs.</para> + </listitem> + </itemizedlist> + </para> + <sect3> + <title>Shadow Copy Setup</title> + <para> + 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 newer server running.</para> + </formalpara> + </listitem> + <listitem> + <formalpara> + <title>Install & Configure LVM</title> + <para> + 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> + 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> + 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> + 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> + Create the physical volume with <command>pvcreate + /dev/hdb1</command></para> + </listitem> + <listitem> + <para> + Create the volume group with and add /dev/hda1 to it + with <command>vgcreate shadowvol /dev/hdb1</command> + </para> + <para> + You can use <command>vgdisplay</command> to review + information about the volume group.</para> + </listitem> + <listitem> + <para> + Now you can create the logical volume with something + like <command>lvcreate -L400M -nsh_test + shadowvol</command></para> + <para> + This creates the logical volume of 400MB's 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> + 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> + 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> + Now we have an LVM volume where we can play with the + shadow_copy VFS module.</para> + </listitem> + <listitem> + <para> + Now we need to prepare the directory with something + like <command>mkdir -p /data/shadow_share</command> + or whatever you want to name your shadow copy + enabled Samba share. Make sure you set the + permissions such 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> + Mount the LVM volume using something like + <command>mount /dev/shadowvol/sh_test + /data/shadow_share</command></para> + <para> + 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> + <para> + <smbconfexample id="vfsshadow"> + <title>Share With shadow_copy VFS</title> + <smbconfsection>[shadow_share]</smbconfsection> + <smbconfoption><name>comment</name><value>Shadow Copy Enabled Share</value></smbconfoption> + <smbconfoption><name>path</name><value>/data/shadow_share</value></smbconfoption> + <smbconfoption><name>vfs objects</name><value>shadow_copy</value></smbconfoption> + <smbconfoption><name>writeable</name><value>yes</value></smbconfoption> + <smbconfoption><name>browseable</name><value>yes</value></smbconfoption> + </smbconfexample> + </para> + </listitem> + <listitem> + <formalpara> + <title>Create Snapshots and Make Them Available to shadow_copy.so</title> + <para> + 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> |