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-%%
-%%
-
-\chapter{DVD Volumes}
-\label{_DVDChapterStart}
-\index[general]{DVD Volumes}
-\index[general]{Writing DVDs}
-\index[general]{DVD Writing}
-\index[general]{Volumes!DVD}
-
-Bacula allows you to specify that you want to write to DVD. However,
-this feature is implemented only in version 1.37 or later.
-You may in fact write to DVD+RW, DVD+R, DVD-R, or DVD-RW
-media. The actual process used by Bacula is to first write
-the image to a spool directory, then when the Volume reaches
-a certain size or, at your option, at the end of a Job, Bacula
-will transfer the image from the spool directory to the
-DVD. The actual work of transferring the image is done
-by a script {\bf dvd-handler}, and the heart of that
-script is a program called {\bf growisofs} which allows
-creating or adding to a DVD ISO filesystem.
-
-You must have {\bf dvd+rw-tools} loaded on your system for DVD writing to
-work. Please note that the original {\bf dvd+rw-tools} package does {\bf
-NOT} work with Bacula. You must apply a patch which can be found in the
-{\bf patches} directory of Bacula sources with the name
-{\bf dvd+rw-tools-5.21.4.10.8.bacula.patch} for version 5.21 of the tools,
-or patch {bf dvd+rw-tools-6.1.bacula.patch} if you have version 6.1
-on your system. Unfortunately, this requires you to build the dvd\_rw-tools
-from source.
-
-Note, some Linux distros such as Debian dvd+rw-tools-7.0-4 package already
-have the patch applied, so please check.
-
-The fact that Bacula cannot use the OS to write directly
-to the DVD makes the whole process a bit more error prone than
-writing to a disk or a tape, but nevertheless, it does work if you
-use some care to set it up properly. However, at the current time
-(version 1.39.30 -- 12 December 2006) we still consider this code to be
-BETA quality. As a consequence, please do careful testing before relying
-on DVD backups in production.
-
-The remainder of this chapter explains the various directives that you can
-use to control the DVD writing.
-
-\label{DVDdirectives}
-\section{DVD Specific SD Directives}
-\index[general]{Directives!DVD}
-\index[general]{DVD Specific SD Directives }
-
-The following directives are added to the Storage daemon's
-Device resource.
-
-\begin{description}
-
-\item [Requires Mount = {\it Yes|No}]
- \index[general]{Requires Mount }
- You must set this directive to {\bf yes} for DVD-writers, and to {\bf no} for
- all other devices (tapes/files). This directive indicates if the device
- requires to be mounted using the {\bf Mount Command}.
- To be able to write a DVD, the following directives must also be
- defined: {\bf Mount Point}, {\bf Mount Command}, {\bf Unmount Command} and
- {\bf Write Part Command}.
-
-\item [Mount Point = {\it directory}]
- \index[general]{Mount Point}
- Directory where the device can be mounted.
-
-\item [Mount Command = {\it name-string}]
- \index[general]{Mount Command}
- Command that must be executed to mount the device. Although the
- device is written directly, the mount command is necessary in
- order to determine the free space left on the DVD. Before the command is
- executed, \%a is replaced with the Archive Device, and \%m with the Mount
- Point.
-
- Most frequently, you will define it as follows:
-
-\footnotesize
-\begin{verbatim}
- Mount Command = "/bin/mount -t iso9660 -o ro %a %m"
-\end{verbatim}
-\normalsize
-
-However, if you have defined a mount point in /etc/fstab, you might be
-able to use a mount command such as:
-
-\footnotesize
-\begin{verbatim}
- Mount Command = "/bin/mount /media/dvd"
-\end{verbatim}
-\normalsize
-
-
-\item [Unmount Command = {\it name-string}]
- \index[general]{Unmount Command}
- Command that must be executed to unmount the device. Before the command is
- executed, \%a is replaced with the Archive Device, and \%m with the Mount
- Point.
-
- Most frequently, you will define it as follows:
-
-\footnotesize
-\begin{verbatim}
- Unmount Command = "/bin/umount %m"
-\end{verbatim}
-\normalsize
-
-\item [Write Part Command = {\it name-string}]
- \index[general]{Write Part Command }
- Command that must be executed to write a part to the device. Before the
- command is executed, \%a is replaced with the Archive Device, \%m with the
- Mount Point, \%e is replaced with 1 if we are writing the first part,
- and with 0 otherwise, and \%v with the current part filename.
-
- For a DVD, you will most frequently specify the Bacula supplied {\bf
- dvd-handler} script as follows:
-
-\footnotesize
-\begin{verbatim}
- Write Part Command = "/path/dvd-handler %a write %e %v"
-\end{verbatim}
-\normalsize
-
- Where {\bf /path} is the path to your scripts install directory, and
- dvd-handler is the Bacula supplied script file.
- This command will already be present, but commented out,
- in the default bacula-sd.conf file. To use it, simply remove
- the comment (\#) symbol.
-
-
-\item [Free Space Command = {\it name-string}]
- \index[general]{Free Space Command }
- Command that must be executed to check how much free space is left on the
- device. Before the command is executed,\%a is replaced with the Archive
- Device.
-
- For a DVD, you will most frequently specify the Bacula supplied {\bf
- dvd-handler} script as follows:
-
-\footnotesize
-\begin{verbatim}
- Free Space Command = "/path/dvd-handler %a free"
-\end{verbatim}
-\normalsize
-
- Where {\bf /path} is the path to your scripts install directory, and
- dvd-handler is the Bacula supplied script file.
- If you want to specify your own command, please look at the code in
- dvd-handler to see what output Bacula expects from this command.
- This command will already be present, but commented out,
- in the default bacula-sd.conf file. To use it, simply remove
- the comment (\#) symbol.
-
- If you do not set it, Bacula will expect there is always free space on the
- device.
-
-\end{description}
-
-In addition to the directives specified above, you must also
-specify the other standard Device resource directives. Please see the
-sample DVD Device resource in the default bacula-sd.conf file. Be sure
-to specify the raw device name for {\bf Archive Device}. It should
-be a name such as {\bf /dev/cdrom} or {\bf /media/cdrecorder} or
-{\bf /dev/dvd} depending on your system. It will not be a name such
-as {\bf /mnt/cdrom}.
-
-Finally, for {\bf growisofs} to work, it must be able to lock
-a certain amount of memory in RAM. If you have restrictions on
-this function, you may have failures. Under {\bf bash}, you can
-set this with the following command:
-
-\footnotesize
-\begin{verbatim}
-ulimit -l unlimited
-\end{verbatim}
-\normalsize
-
-\section{Edit Codes for DVD Directives}
-\index[general]{Directives!DVD Edit Codes}
-\index[general]{Edit Codes for DVD Directives }
-
-Before submitting the {\bf Mount Command}, {\bf Unmount Command},
-{\bf Write Part Command}, or {\bf Free Space Command} directives
-to the operating system, Bacula performs character substitution of the
-following characters:
-
-\footnotesize
-\begin{verbatim}
- %% = %
- %a = Archive device name
- %e = erase (set if cannot mount and first part)
- %n = part number
- %m = mount point
- %v = last part name (i.e. filename)
-\end{verbatim}
-\normalsize
-
-
-
-\section{DVD Specific Director Directives}
-\index[general]{Directives!DVD}
-\index[general]{DVD Specific Director Directives }
-
-The following directives are added to the Director's Job resource.
-
-\label{WritePartAfterJob}
-\begin{description}
-\item [Write Part After Job = \lt{}yes|no\gt{}]
- \index[general]{Write Part After Job }
- If this directive is set to {\bf yes} (default {\bf no}), the
- Volume written to a temporary spool file for the current Job will
- be written to the DVD as a new part file
- will be created after the job is finished.
-
- It should be set to {\bf yes} when writing to devices that require a mount
- (for example DVD), so you are sure that the current part, containing
- this job's data, is written to the device, and that no data is left in
- the temporary file on the hard disk. However, on some media, like DVD+R
- and DVD-R, a lot of space (about 10Mb) is lost everytime a part is
- written. So, if you run several jobs each after another, you could set
- this directive to {\bf no} for all jobs, except the last one, to avoid
- wasting too much space, but to ensure that the data is written to the
- medium when all jobs are finished.
-
- This directive is ignored for devices other than DVDs.
-\end{description}
-
-
-
-\label{DVDpoints}
-\section{Other Points}
-\index[general]{Points!Other }
-\index[general]{Other Points }
-
-\begin{itemize}
-\item Please be sure that you have any automatic DVD mounting
- disabled before running Bacula -- this includes auto mounting
- in /etc/fstab, hotplug, ... If the DVD is automatically
- mounted by the OS, it will cause problems when Bacula tries
- to mount/unmount the DVD.
-\item Please be sure that you the directive {\bf Write Part After Job}
- set to {\bf yes}, otherwise the last part of the data to be
- written will be left in the DVD spool file and not written to
- the DVD. The DVD will then be unreadable until this last part
- is written. If you have a series of jobs that are run one at
- a time, you can turn this off until the last job is run.
-\item The current code is not designed to have multiple simultaneous
- jobs writing to the DVD. As a consequence, please ensure that
- only one DVD backup job runs at any time.
-\item Writing and reading of DVD+RW seems to work quite reliably
- provided you are using the patched dvd+rw-mediainfo programs.
- On the other hand, we do not have enough information to ensure
- that DVD-RW or other forms of DVDs work correctly.
-\item DVD+RW supports only about 1000 overwrites. Every time you
- mount the filesystem read/write will count as one write. This can
- add up quickly, so it is best to mount your DVD+RW filesystem read-only.
- Bacula does not need the DVD to be mounted read-write, since it uses
- the raw device for writing.
-\item Reformatting DVD+RW 10-20 times can apparently make the medium
- unusable. Normally you should not have to format or reformat
- DVD+RW media. If it is necessary, current versions of growisofs will
- do so automatically.
-\item We have had several problems writing to DVD-RWs (this does NOT
- concern DVD+RW), because these media have two writing-modes: {\bf
- Incremental Sequential} and {\bf Restricted Overwrite}. Depending on
- your device and the media you use, one of these modes may not work
- correctly (e.g. {\bf Incremental Sequential} does not work with my NEC
- DVD-writer and Verbatim DVD-RW).
-
- To retrieve the current mode of a DVD-RW, run:
-\begin{verbatim}
- dvd+rw-mediainfo /dev/xxx
-\end{verbatim}
- where you replace xxx with your DVD device name.
-
- {\bf Mounted Media} line should give you the information.
-
- To set the device to {\bf Restricted Overwrite} mode, run:
-\begin{verbatim}
- dvd+rw-format /dev/xxx
-\end{verbatim}
- If you want to set it back to the default {\bf Incremental Sequential} mode, run:
-\begin{verbatim}
- dvd+rw-format -blank /dev/xxx
-\end{verbatim}
-
-\item Bacula only accepts to write to blank DVDs. To quickly blank a DVD+/-RW, run
- this command:
-\begin{verbatim}
- dd if=/dev/zero bs=1024 count=512 | growisofs -Z /dev/xxx=/dev/fd/0
-\end{verbatim}
- Then, try to mount the device, if it cannot be mounted, it will be considered
- as blank by Bacula, if it can be mounted, try a full blank (see below).
-
-\item If you wish to blank completely a DVD+/-RW, use the following:
-\begin{verbatim}
- growisofs -Z /dev/xxx=/dev/zero
-\end{verbatim}
- where you replace xxx with your DVD device name. However, note that this
- blanks the whole DVD, which takes quite a long time (16 minutes on mine).
-\item DVD+RW and DVD-RW support only about 1000 overwrites (i.e. don't use the
-same medium for years if you don't want to have problems...).
-
-To write to the DVD the first time use:
-\begin{verbatim}
- growisofs -Z /dev/xxx filename
-\end{verbatim}
-
-To add additional files (more parts use):
-
-\begin{verbatim}
- growisofs -M /dev/xxx filename
-\end{verbatim}
-
-The option {\bf -use-the-force-luke=4gms} was added in growisofs 5.20 to
-override growisofs' behavior of always checking for the 4GB limit.
-Normally, this option is recommended for all Linux 2.6.8 kernels or
-greater, since these newer kernels can handle writing more than 4GB.
-See below for more details on this subject.
-
-\item For more information about DVD writing, please look at the
-\elink{dvd+rw-tools homepage}{http://fy.chalmers.se/~appro/linux/DVD+RW/}.
-
-\item According to bug \#912, bscan cannot read multi-volume DVDs. This is
-on our TODO list, but unless someone submits a patch it is not likely to be
-done any time in the near future. (9 Sept 2007).
-
-\end{itemize}
projects / bacula / docs / blobdiff