5 \label{_DVDChapterStart}
6 \index[general]{DVD Volumes}
7 \index[general]{Writing DVDs}
8 \index[general]{DVD Writing}
9 \index[general]{Volumes!DVD}
10 \addcontentsline{toc}{section}{DVD Volumes}
12 Bacula allows you to specify that you want to write to DVD. However,
13 this feature is implemented only in version 1.37 or later.
14 You may in fact write to DVD+RW, DVD+R, DVD-R, or DVD-RW
15 media. The actual process used by Bacula is to first write
16 the image to a spool directory, then when the Volume reaches
17 a certain size or, at your option, at the end of a Job, Bacula
18 will transfer the image from the spool directory to the
19 DVD. The actual work of transferring the image is done
20 by a script {\bf dvd-writepart}, and the heart of that
21 script is a program called {\bf growisofs} which allows
22 creating or adding to a DVD ISO filesystem. growisofs is
23 normally found in the {\bf dvd+rw-tools} package or rpm.
24 You must have it loaded on your system for DVD writing to
27 The fact that Bacula cannot use the OS to write directly
28 to the DVD makes the whole process a bit more error prone than
29 writing to say a disk, but nevertheless, it does work if you
30 use some care to set it up properly.
32 The remainder of this chapter explains the various directives that you can
33 use to control the DVD writing.
37 \subsection*{DVD Specific SD Directives}
38 \index[general]{Directives!DVD}
39 \index[general]{DVD Specific SD Directives }
40 \addcontentsline{toc}{subsection}{DVD Specific SD Directives}
42 The following directives are added to the Storage daemon's
47 \item [Requires Mount = {\it Yes|No}]
48 \index[sd]{Requires Mount }
49 You must set this directive to {\bf yes} for DVD-writers, and to {\bf no} for
50 all other devices (tapes/files). This directive indicates if the device
51 requires to be mounted to be read, and if it must be written in a special way.
52 If it set, {\bf Mount Point}, {\bf Mount Command}, {\bf Unmount Command} and
53 {\bf Write Part Command} directives must also be defined.
55 \item [Mount Point = {\it directory}]
56 \index[sd]{Mount Point }
57 Directory where the device can be mounted.
59 \item [Mount Command = {\it name-string}]
60 \index[sd]{Mount Command }
61 Command that must be executed to mount the device. Although the
62 device is written directly, the mount command is necessary in
63 order to determine the free space left on the DVD. Before the command is
64 executed, \%a is replaced with the Archive Device, and \%m with the Mount
67 Most frequently, you will define it as follows:
71 Mount Command = "/bin/mount -t iso9660 -o ro %a %m"
75 \item [Unmount Command = {\it name-string}]
76 \index[sd]{Unmount Command }
77 Command that must be executed to unmount the device. Before the command is
78 executed, \%a is replaced with the Archive Device, and \%m with the Mount
81 Most frequently, you will define it as follows:
85 Unmount Command = "/bin/umount %m"
89 \item [Write Part Command = {\it name-string}]
90 \index[sd]{Write Part Command }
91 Command that must be executed to write a part to the device. Before the
92 command is executed, \%a is replaced with the Archive Device, \%m with the
93 Mount Point, \%n with the current part number (0-based), and \%v with the
94 current part filename.
96 For a DVD, you will most frequently specify the Bacula supplied {\bf
97 dvd-writepart} script as follows:
101 Write Part Command = "/path/dvd-writepart %n %a %v"
105 Where {\bf /path} is the path to your scripts install directory, and
106 dvd-writepart is the Bacula supplied script file.
107 This command will already be present, but commented out,
108 in the default bacula-sd.conf file. To use it, simply remove
109 the comment (#) symbol.
112 \item [Free Space Command = {\it name-string}]
113 \index[sd]{Free Space Command }
114 Command that must be executed to check how much free space is left on the
115 device. Before the command is executed, \%a is replaced with the Archive
116 Device, \%m with the Mount Point, \%n with the current part number (0-based),
117 and \%v with the current part filename.
119 For a DVD, you will most frequently specify the Bacula supplied {\bf
120 dvd-freespace} script as follows:
124 Free Space Command = "/path/dvd-freespace %n %a"
128 Where {\bf /path} is the path to your scripts install directory, and
129 dvd-freespace is the Bacula supplied script file.
130 If you want to specify your own command, please look at the code in
131 dvd-freespace to see what output Bacula expects from this command.
132 This command will already be present, but commented out,
133 in the default bacula-sd.conf file. To use it, simply remove
134 the comment (#) symbol.
136 If you do not set it, Bacula will expect there is always free space on the
141 In addition to the directives specified above, you must also
142 specify the other standard Device resource directives. Please see the
143 sample DVD Device resource in the default bacula-sd.conf file. Be sure
144 to specify the raw device name for {\bf Archive Device}. It should
145 be a name such as {\bf /dev/cdrom} or {\bf /media/cdrecorder} or
146 {\bf /dev/dvd} depending on your system. It will not be a name such
150 \subsection*{DVD Specific Director Directives}
151 \index[general]{Directives!DVD}
152 \index[general]{DVD Specific Director Directives }
153 \addcontentsline{toc}{subsection}{DVD Specific Director Directives}
155 The following directives are added to the Director's Job resource.
157 \label{WritePartAfterJob}
158 \item [Write Part After Job = \lt{}yes|no\gt{}]
159 \index[dir]{Write Part After Job }
160 If this directive is set to {\bf yes} (default {\bf no}), the
161 Volume written to a temporary spool file for the current Job will
162 be written to the DVD as a new part file
163 will be created after the job is finished.
165 It should be set to {\bf yes} when writing to devices that require a mount
166 (for example DVD), so you are sure that the current part, containing
167 this job's data, is written to the device, and that no data is left in
168 the temporary file on the hard disk. However, on some media, like DVD+R
169 and DVD-R, a lot of space (about 10Mb) is lost everytime a part is
170 written. So, if you run several jobs each after another, you could set
171 this directive to {\bf no} for all jobs, except the last one, to avoid
172 wasting too much space, but to ensure that the data is written to the
173 medium when all jobs are finished.
175 It is ignored with tape and FIFO devices.
181 \subsection*{Other Points}
182 \index[general]{Points!Other }
183 \index[general]{Other Points }
184 \addcontentsline{toc}{subsection}{Other Points}
187 \item DVD+RW supports only about 1000 overwrites, so every time you
188 mount the filesystem read/write will count as one write. This can
189 add up quickly, so it is best to mount your DVD+RW filesystem read-only.
190 \item Reformating DVD+RW 10-20 time can apparently make the medium
191 unusable. Normally you should not have to format or reformat
192 DVD+RW media. If it is necessary, current versions of growisofs will
194 \item If you wish to blank your DVD, use the following:
196 growisofs -Z /dev/xxx=/dev/zero
198 where you replace xxx with your DVD device name.