4 \section*{Autochanger Support}
5 \label{_ChapterStart18}
6 \index[general]{Support!Autochanger }
7 \index[general]{Autochanger Support }
8 \addcontentsline{toc}{section}{Autochanger Support}
10 \subsection*{Autochangers -- General}
11 \index[general]{General!Autochangers -- }
12 \index[general]{Autochangers -- General }
13 \addcontentsline{toc}{subsection}{Autochangers -- General}
15 Bacula provides autochanger support for reading and writing tapes. In
16 order to work with an autochanger, Bacula requires a number of things, each of
17 which is explained in more detail after this list:
20 \item A script that actually controls the autochanger according to commands
21 sent by Bacula. We furnish such a script that works with {\bf mtx} found in
22 the {\bf depkgs} distribution. This script works only with single drive
24 \item That each Volume (tape) to be used must be defined in the Catalog and
25 have a Slot number assigned to it so that Bacula knows where the Volume is in
26 the autochanger. This is generally done with the {\bf label} command. See
27 below for more details. You must pre-label the tapes manually before
29 \item Modifications to your Storage daemon's Device configuration resource to
30 identify that the device is a changer, as well as a few other parameters.
31 \item You should also modify your Storage resource definition in the
32 Director's configuration file so that you are automatically prompted for the
33 Slot when labeling a Volume.
34 \item You need to ensure that your Storage daemon (if not running as root)
35 has access permissions to both the tape drive and the control device.
36 \item You need to have {\bf Autochanger = yes} in your Storage resource
37 in your bacula-dir.conf file so that you will be prompted for the
38 slot number when you label Volumes.
41 In version 1.37 and later, there is a new \ilink{Autochanger
42 resource}{AutochangerRes} that permits you to group Device resources thus
43 creating a multi-drive autochanger. If you have an autochanger,
44 you must use this new resource.
46 Bacula uses its own {\bf mtx-changer} script to interface with a program
47 that actually does the tape changing. Thus in principle, {\bf mtx-changer}
48 can be adapted to function with any autochanger program. The current
49 version of {\bf mtx-changer} works with the {\bf mtx} program. However,
50 FreeBSD users have provided a script in the {\bf examples/autochangers}
51 directory that allows Bacula to use the {\bf chio} program.
53 Bacula also supports autochangers with barcode
54 readers. This support includes two Console commands: {\bf label barcodes}
55 and {\bf update slots}. For more details on these commands, see the "Barcode
56 Support" section below.
58 Current Bacula autochanger support does not include cleaning, stackers, or
59 silos. However, under certain conditions, you may be able to make Bacula
60 work with stackers (gravity feed and such). Support for multi-drive
61 autochangers requires the \ilink{Autochanger resource}{AutochangerRes}
62 introduced in version 1.37. This resource is also recommended for single
65 In principle, if {\bf mtx} will operate your changer correctly, then it is
66 just a question of adapting the {\bf mtx-changer} script (or selecting one
67 already adapted) for proper interfacing. You can find a list of autochangers
68 supported by {\bf mtx} at the following link:
69 \elink{http://mtx.badtux.net/compatibility.php}
70 {http://mtx.badtux.net/compatibility.php}.
71 The home page for the {\bf mtx} project can be found at:
72 \elink{http://mtx.badtux.net/}{http://mtx.badtux.net/}.
74 If you are having troubles, please use the {\bf auto} command in the {\bf
75 btape} program to test the functioning of your autochanger with Bacula. When
76 Bacula is running, please remember that for many distributions (e.g. FreeBSD,
77 Debian, ...) the Storage daemon runs as {\bf bacula.tape} rather than {\bf
78 root.root}, so you will need to ensure that the Storage daemon has sufficient
79 permissions to access the autochanger.
82 \subsection*{Knowing What SCSI Devices You Have}
83 \index[general]{Have!Knowing What SCSI Devices You }
84 \index[general]{Knowing What SCSI Devices You Have }
85 \index[general]{SCSI devices}
86 \index[general]{devices!SCSI}
87 \addcontentsline{toc}{subsection}{Knowing What SCSI Devices You Have}
97 to see what SCSI devices you have available. You can also:
101 cat /proc/scsi/sg/device_hdr /proc/scsi/sg/devices
105 to find out how to specify their control address ({\bf /dev/sg0} for the
106 first, {\bf /dev/sg1} for the second, ...) on the {\bf Changer Device = }
109 Under FreeBSD, you can use:
117 To list the SCSI devices as well as the {\bf /dev/passn} that you will use on
118 the Bacula {\bf Changer Device = } directive.
120 Please check that your Storage daemon has permission to access this
123 The following tip for FreeBSD users comes from Danny Butroyd:
124 n reboot bacula will NOT have permissions to
125 control the device /dev/pass0 (assuming this is your changer device).
126 To get around this just edit the /etc/devfs.conf file and add the
127 following to the bottom of the config file:
130 own pass0 root:bacula
132 own nsa0.0 root:bacula
136 I have given the bacula group permission to write to the nsa0.0 device
137 too just to be on the safe side. To bring these changes into effect
140 /etc/rc.d/devfs restart
142 Basically this will stop you having to change permissions on these
143 devices to make bacula work when operating the AutoChanger after a reboot.
147 \subsection*{Example Scripts}
148 \index[general]{Scripts!Example }
149 \index[general]{Example Scripts }
150 \addcontentsline{toc}{subsection}{Example Scripts}
152 Please read the sections below so that you understand how autochangers work
153 with Bacula. Although we supply a default {\bf mtx-changer} script, your
154 autochanger may require some additional changes. If you want to see examples
155 of configuration files and scripts, please look in the {\bf
156 \lt{}bacula-src\gt{}/examples/devices} directory where you will find an
157 example {\bf HP-autoloader.conf} Bacula Device resource, and several {\bf
158 mtx-changer} scripts that have been modified to work with different
164 \index[general]{Slots }
165 \addcontentsline{toc}{subsection}{Slots}
167 To properly address autochangers, Bacula must know which Volume is in each
168 {\bf slot} of the autochanger. Slots are where the changer cartridges reside
169 when not loaded into the drive. Bacula numbers these slots from one to the
170 number of cartridges contained in the autochanger.
172 Bacula will not automatically use a Volume in your autochanger unless it is
173 labeled and the slot number is stored in the catalog and the Volume is marked
174 as InChanger. For each Volume in your
175 changer, you will, using the Console program, assign a slot. This information
176 is kept in {\bf Bacula's} catalog database along with the other data for the
177 volume. If no slot is given, or the slot is set to zero, Bacula will not
178 attempt to use the autochanger even if all the necessary configuration records
179 are present. In addition, the console {\bf mount} command does not cause
180 Bacula to operate the autochanger, it only tells Bacula to read any tape that
183 You can check if the Slot number and InChanger flag are set by doing a:
188 in the Console program.
191 \subsection*{Multiple Devices}
192 \index[general]{Devices!Multiple }
193 \index[general]{Multiple Devices }
194 \addcontentsline{toc}{subsection}{Multiple Devices}
196 Some autochangers have more than one read/write device (drive). The
198 \ilink{Autochanger resource}{AutochangerRes} introduced in version
199 1.37 permits you to group Device resources, where each device
200 represents a drive. The Director may still reference the Devices (drives)
201 directly, but doing so, bypasses the proper functioning of the
202 drives together. Instead, the Director (in the Storage resource)
203 should reference the Autochanger resource name. Doing so permits
204 the Storage daemon to ensure that only one drive uses the mtx-changer
205 script at a time, and also that two drives don't reference the
208 Multi-drive requires the use of the {\bf
209 Drive Index} directive in the Device resource of the Storage daemon's
210 configuration file. Drive numbers or the Device Index are numbered beginning
211 at zero, which is the default. To use the second Drive in an autochanger, you
212 need to define a second Device resource and set the Drive Index to 1 for
213 that device. In general, the second device will have the same {\bf Changer
214 Device} (control channel) as the first drive, but a different {\bf Archive
217 \label{ConfigRecords}
218 \subsection*{Device Configuration Records}
219 \index[general]{Records!Device Configuration }
220 \index[general]{Device Configuration Records }
221 \addcontentsline{toc}{subsection}{Device Configuration Records}
223 Configuration of autochangers within Bacula is done in the Device resource of
224 the Storage daemon. Four records: {\bf Autochanger}, {\bf Changer Device},
225 {\bf Changer Command}, and {\bf Maximum Changer Wait} control how Bacula uses
228 These four records, permitted in {\bf Device} resources, are described in
229 detail below. Note, however, that the {\bf Changer Device} and the
230 {\bf Changer Command} directives are not needed in the Device resource
231 if they are present in the {\bf Autochanger} resource.
235 \item [Autochanger = {\it Yes|No} ]
236 \index[sd]{Autochanger }
237 The {\bf Autochanger} record specifies that the current device is or is not
238 an autochanger. The default is {\bf no}.
240 \item [Changer Device = \lt{}device-name\gt{}]
241 \index[sd]{Changer Device }
242 In addition to the Archive Device name, you must specify a {\bf Changer
243 Device} name. This is because most autochangers are controlled through a
244 different device than is used for reading and writing the cartridges. For
245 example, on Linux, one normally uses the generic SCSI interface for
246 controlling the autochanger, but the standard SCSI interface for reading and
247 writing the tapes. On Linux, for the {\bf Archive Device = /dev/nst0}, you
248 would typically have {\bf Changer Device = /dev/sg0}. Note, some of the more
249 advanced autochangers will locate the changer device on {\bf /dev/sg1}. Such
250 devices typically have several drives and a large number of tapes.
252 On FreeBSD systems, the changer device will typically be on {\bf /dev/pass0}
253 through {\bf /dev/passn}.
255 On Solaris, the changer device will typically be some file under {\bf
258 Please ensure that your Storage daemon has permission to access this
261 \item [Changer Command = \lt{}command\gt{}]
262 \index[sd]{Changer Command }
263 This record is used to specify the external program to call and what
264 arguments to pass to it. The command is assumed to be a standard program or
265 shell script that can be executed by the operating system. This command is
266 invoked each time that Bacula wishes to manipulate the autochanger. The
267 following substitutions are made in the {\bf command} before it is sent to
268 the operating system for execution:
273 %a = archive device name
274 %c = changer device name
275 %d = changer drive index base 0
278 %o = command (loaded, load, or unload)
285 An actual example for using {\bf mtx} with the {\bf mtx-changer} script (part
286 of the Bacula distribution) is:
290 Changer Command = "/etc/bacula/mtx-changer %c %o %S %a %d"
294 Where you will need to adapt the {\bf /etc/bacula} to be the actual path on
295 your system where the mtx-changer script resides. Details of the three
296 commands currently used by Bacula (loaded, load, unload) as well as the
297 output expected by Bacula are give in the {\bf Bacula Autochanger Interface}
300 \item [Maximum Changer Wait = \lt{}time\gt{}]
301 \index[sd]{Maximum Changer Wait }
302 This record is used to define the maximum amount of time that Bacula
303 will wait for an autoloader to respond to a command (e.g. load). The
304 default is set to 120 seconds. If you have a slow autoloader you may
305 want to set it longer.
307 If the autoloader program fails to respond in this time, it will be killed
308 and Bacula will request operator intervention.
310 \item [Drive Index = \lt{}number\gt{}]
311 \index[sd]{Drive Index }
312 This record allows you to tell Bacula to use the second or subsequent
313 drive in an autochanger with multiple drives. Since the drives are
314 numbered from zero, the second drive is defined by
323 To use the second drive, you need a second Device resource definition in the
324 Bacula configuration file. See the Multiple Drive section above in this
325 chapter for more information.
328 In addition, for proper functioning of the Autochanger, you must
329 define an Autochanger resource.
330 \input{autochangerres}
333 \subsection*{An Example Configuration File}
334 \index[general]{Example Configuration File }
335 \index[general]{File!Example Configuration }
336 \addcontentsline{toc}{subsection}{Example Configuration File}
338 The following two resources implement an autochanger:
345 Changer Device = /dev/sg0
346 Changer Command = "/etc/bacula/mtx-changer %c %o %S %a %d"
352 Archive Device = /dev/nst0 # Normal archive device
355 AutomaticMount = yes;
361 where you will adapt the {\bf Archive Device}, the {\bf Changer Device}, and
362 the path to the {\bf Changer Command} to correspond to the values used on your
365 \subsection*{A Multi-drive Example Configuration File}
366 \index[general]{Multi-drive Example Configuration File }
367 \addcontentsline{toc}{subsection}{A Multi-drive Example Configuration File}
369 The following resources implement a multi-drive autochanger:
375 Device = Drive-1, Drive-2
376 Changer Device = /dev/sg0
377 Changer Command = "/etc/bacula/mtx-changer %c %o %S %a %d"
384 Archive Device = /dev/nst0 # Normal archive device
387 AutomaticMount = yes;
395 Archive Device = /dev/nst1 # Normal archive device
398 AutomaticMount = yes;
405 where you will adapt the {\bf Archive Device}, the {\bf Changer Device}, and
406 the path to the {\bf Changer Command} to correspond to the values used on your
409 \label{SpecifyingSlots}
410 \subsection*{Specifying Slots When Labeling}
411 \index[general]{Specifying Slots When Labeling }
412 \index[general]{Labeling!Specifying Slots When }
413 \addcontentsline{toc}{subsection}{Specifying Slots When Labeling}
415 If you add an {\bf Autochanger = yes} record to the Storage resource in your
416 Director's configuration file, the Bacula Console will automatically prompt
417 you for the slot number when the Volume is in the changer when
418 you {\bf add} or {\bf label} tapes for that Storage device. If your
419 {\bf mtx-changer} script is properly installed, Bacula will automatically
420 load the correct tape during the label command.
423 {\bf Autochanger = yes} in the Storage daemon's Device resource
424 as we have described above in
425 order for the autochanger to be used. Please see the
426 \ilink{Storage Resource}{Autochanger1} in the Director's chapter
428 \ilink{Device Resource}{Autochanger} in the Storage daemon
429 chapter for more details on these records.
431 Thus all stages of dealing with tapes can be totally automated. It is also
432 possible to set or change the Slot using the {\bf update} command in the
433 Console and selecting {\bf Volume Parameters} to update.
435 Even though all the above configuration statements are specified and correct,
436 Bacula will attempt to access the autochanger only if a {\bf slot} is non-zero
437 in the catalog Volume record (with the Volume name).
439 If your autochanger has barcode labels, you can label all the Volumes in
440 your autochanger one after another by using the {\bf label barcodes} command.
441 For each tape in the changer containing a barcode, Bacula will mount the tape
442 and then label it with the same name as the barcode. An appropriate Media
443 record will also be created in the catalog. Any barcode that begins with the
444 same characters as specified on the "CleaningPrefix=xxx" command, will be
445 treated as a cleaning tape, and will not be labeled. For example with:
447 Please note that Volumes must be pre-labeled to be automatically used in
448 the autochanger during a backup. If you do not have a barcode reader, this
449 is done manually (or via a script).
455 Cleaning Prefix = "CLN"
460 Any slot containing a barcode of CLNxxxx will be treated as a cleaning tape
461 and will not be mounted.
463 \subsection*{Changing Cartridges}
464 \index[general]{Changing Cartridges }
465 \addcontentsline{toc}{subsection}{Changing Cartridges}
466 If you wish to insert or remove cartridges in your autochanger or
467 you manually run the {\bf mtx} program, you must first tell Bacula
468 to release the autochanger by doing:
473 (change cartridges and/or run mtx)
478 If you do not do the unmount before making such a change, Bacula
479 will become completely confused about what is in the autochanger
480 and may stop function because it expects to have exclusive use
481 of the autochanger while it has the drive mounted.
485 \subsection*{Dealing with Multiple Magazines}
486 \index[general]{Dealing with Multiple Magazines }
487 \index[general]{Magazines!Dealing with Multiple }
488 \addcontentsline{toc}{subsection}{Dealing with Multiple Magazines}
490 If you have several magazines or if you insert or remove cartridges from a
491 magazine, you should notify Bacula of this. By doing so, Bacula will as
492 a preference, use Volumes that it knows to be in the autochanger before
493 accessing Volumes that are not in the autochanger. This prevents unneeded
494 operator intervention.
496 If your autochanger has barcodes (machine readable tape labels), the task of
497 informing Bacula is simple. Every time, you change a magazine, or add or
498 remove a cartridge from the magazine, simply do
504 (insert new magazine)
510 in the Console program. This will cause Bacula to request the autochanger to
511 return the current Volume names in the magazine. This will be done without
512 actually accessing or reading the Volumes because the barcode reader does this
513 during inventory when the autochanger is first turned on. Bacula will ensure
514 that any Volumes that are currently marked as being in the magazine are marked
515 as no longer in the magazine, and the new list of Volumes will be marked as
516 being in the magazine. In addition, the Slot numbers of the Volumes will be
517 corrected in Bacula's catalog if they are incorrect (added or moved).
519 If you do not have a barcode reader on your autochanger, you have several
523 \item You can manually set the Slot and InChanger flag using the {\bf update
524 volume} command in the Console (quite painful).
526 \item You can issue a
534 command that will cause Bacula to read the label on each of the cartridges in
535 the magazine in turn and update the information (Slot, InChanger flag) in the
536 catalog. This is quite effective but does take time to load each cartridge
537 into the drive in turn and read the Volume label.
539 \item You can modify the mtx-changer script so that it simulates an
540 autochanger with barcodes. See below for more details.
544 \subsection*{Simulating Barcodes in your Autochanger}
545 \index[general]{Autochanger!Simulating Barcodes in your }
546 \index[general]{Simulating Barcodes in your Autochanger }
547 \addcontentsline{toc}{subsection}{Simulating Barcodes in your Autochanger}
549 You can simulate barcodes in your autochanger by making the {\bf mtx-changer}
550 script return the same information that an autochanger with barcodes would do.
551 This is done by commenting out the one and only line in the {\bf list)} case,
556 ${MTX} -f $ctl status | grep " *Storage Element [0-9]*:.*Full" | awk "{print \$3 \$4}" | sed "s/Full *\(:VolumeTag=\)*//"
560 at approximately line 99 by putting a \# in column one of that line, or by
561 simply deleting it. Then in its place add a new line that prints the contents
562 of a file. For example:
566 cat /etc/bacula/changer.volumes
570 Be sure to include a full path to the file, which can have any name. The
571 contents of the file must be of the following format:
582 Where the 1, 2, 3 are the slot numbers and Volume1, Volume2, ... are the
583 Volume names in those slots. You can have multiple files that represent the
584 Volumes in different magazines, and when you change magazines, simply copy the
585 contents of the correct file into your {\bf /etc/bacula/changer.volumes} file.
586 There is no need to stop and start Bacula when you change magazines, simply
587 put the correct data in the file, then run the {\bf update slots} command, and
588 your autochanger will appear to Bacula to be an autochanger with barcodes.
591 \subsection*{The Full Form of the Update Slots Command}
592 \index[general]{Full Form of the Update Slots Command }
593 \index[general]{Command!Full Form of the Update Slots }
594 \addcontentsline{toc}{subsection}{Full Form of the Update Slots Command}
596 If you change only one cartridge in the magazine, you may not want to scan all
597 Volumes, so the {\bf update slots} command (as well as the {\bf update slots
598 scan} command) has the additional form:
602 update slots=n1,n2,n3-n4, ...
606 where the keyword {\bf scan} can be appended or not. The n1,n2, ... represent
607 Slot numbers to be updated and the form n3-n4 represents a range of Slot
608 numbers to be updated (e.g. 4-7 will update Slots 4,5,6, and 7).
610 This form is particularly useful if you want to do a scan (time expensive) and
611 restrict the update to one or two slots.
613 For example, the command:
617 update slots=1,6 scan
621 will cause Bacula to load the Volume in Slot 1, read its Volume label and
622 update the Catalog. It will do the same for the Volume in Slot 6. The command:
631 will read the barcoded Volume names for slots 1,2,3 and 6 and make the
632 appropriate updates in the Catalog. If you don't have a barcode reader or have
633 not modified the mtx-changer script as described above, the above command will
634 not find any Volume names so will do nothing.
637 \subsection*{FreeBSD Issues}
638 \index[general]{Issues!FreeBSD }
639 \index[general]{FreeBSD Issues }
640 \addcontentsline{toc}{subsection}{FreeBSD Issues}
642 If you are having problems on FreeBSD when Bacula tries to select a tape, and
643 the message is {\bf Device not configured}, this is because FreeBSD has made
644 the tape device {\bf /dev/nsa1} disappear when there is no tape mounted in the
645 autochanger slot. As a consequence, Bacula is unable to open the device. The
646 solution to the problem is to make sure that some tape is loaded into the tape
647 drive before starting Bacula. This problem is corrected in Bacula versions
651 \ilink{ Tape Testing}{FreeBSDTapes} chapter of this manual for
652 {\bf important} information concerning your tape drive before doing the
654 \label{AutochangerTesting}
656 \subsection*{Testing the Autochanger and Adapting Your mtx-changer Script}
657 \index[general]{Testing the Autochanger and Adapting Your mtx-changer Script }
658 \index[general]{Script!Testing the Autochanger and Adapting Your mtx-changer }
659 \addcontentsline{toc}{subsection}{Testing the Autochanger and Adapting Your
662 Before attempting to use the autochanger with Bacula, it is preferable to
663 "hand-test" that the changer works. To do so, we suggest you do the
664 following commands (assuming that the {\bf mtx-changer} script is installed in
665 {\bf /etc/bacula/mtx-changer}):
669 \item [Make sure Bacula is not running.]
671 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ list \ 0 \ /dev/nst0 \ 0]
672 \index[sd]{mtx-changer list}
674 This command should print:
686 or one number per line for each slot that is occupied in your changer, and
687 the number should be terminated by a colon ({\bf :}). If your changer has
688 barcodes, the barcode will follow the colon. If an error message is printed,
689 you must resolve the problem (e.g. try a different SCSI control device name
690 if {\bf /dev/sg0} is incorrect. For example, on FreeBSD systems, the
691 autochanger SCSI control device is generally {\bf /dev/pass2}.
693 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ slots \ 0 \ /dev/nst0 \ 0]
694 \index[sd]{mtx-changer slots}
696 This command should return the number of slots in your autochanger.
698 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ unload \ ]
699 \index[sd]{mtx-changer unload}
701 If a tape is loaded, this should cause it to be unloaded.
703 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ load \ 3 \ /dev/nst0 \ 0 ]
704 \index[sd]{mtx-changer load}
706 Assuming you have a tape in slot 3, it will be loaded into the read slot (0).
709 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ loaded \ 0 \ /dev/nst0 \ 0]
710 \index[sd]{mtx-changer loaded}
714 \item [/etc/bacula/mtx-changer \ /dev/sg0 \ unload]
717 Once all the above commands work correctly, assuming that you have the right
718 {\bf Changer Command} in your configuration, Bacula should be able to operate
719 the changer. The only remaining area of problems will be if your autoloader
720 needs some time to get the tape loaded after issuing the command. After the
721 {\bf mtx-changer} script returns, Bacula will immediately rewind and read the
722 tape. If Bacula gets rewind I/O errors after a tape change, you will probably
723 need to insert a {\bf sleep 20} after the {\bf mtx} command, but be careful to
724 exit the script with a zero status by adding {\bf exit 0} after any additional
725 commands you add to the script. This is because Bacula checks the return
726 status of the script, which should be zero if all went well.
728 You can test whether or not you need a {\bf sleep} by putting the following
729 commands into a file and running it as a script:
734 /etc/bacula/mtx-changer /dev/sg0 unload
735 /etc/bacula/mtx-changer /dev/sg0 load 3
736 mt -f /dev/st0 rewind
741 If the above script runs, you probably have no timing problems. If it does not
742 run, start by putting a {\bf sleep 30} or possibly a {\bf sleep 60} in the
743 script just after the mtx-changer load command. If that works, then you should
744 move the sleep into the actual {\bf mtx-changer} script so that it will be
745 effective when Bacula runs.
747 A second problem that comes up with a small number of autochangers is that
748 they need to have the cartridge ejected before it can be removed. If this is
749 the case, the {\bf load 3} will never succeed regardless of how long you wait.
750 If this seems to be your problem, you can insert an eject just after the
751 unload so that the script looks like:
756 /etc/bacula/mtx-changer /dev/sg0 unload
757 mt -f /dev/st0 offline
758 /etc/bacula/mtx-changer /dev/sg0 load 3
759 mt -f /dev/st0 rewind
764 Obviously, if you need the {\bf offline} command, you should move it into the
765 mtx-changer script ensuring that you save the status of the {\bf mtx} command
766 or always force an {\bf exit 0} from the script, because Bacula checks the
767 return status of the script.
769 As noted earlier, there are several scripts in {\bf
770 \lt{}bacula-source\gt{}/examples/devices} that implement the above features,
771 so they may be a help to you in getting your script to work.
773 If Bacula complains "Rewind error on /dev/nst0. ERR=Input/output error." you
774 most likely need more sleep time in your {\bf mtx-changer} before returning to
775 Bacula after a load command has been completed.
779 \subsection*{Using the Autochanger}
780 \index[general]{Using the Autochanger }
781 \index[general]{Autochanger!Using the }
782 \addcontentsline{toc}{subsection}{Using the Autochanger}
784 Let's assume that you have properly defined the necessary Storage daemon
785 Device records, and you have added the {\bf Autochanger = yes} record to the
786 Storage resource in your Director's configuration file.
788 Now you fill your autochanger with say six blank tapes.
790 What do you do to make Bacula access those tapes?
792 One strategy is to prelabel each of the tapes. Do so by starting Bacula, then
793 with the Console program, enter the {\bf label} command:
798 Connecting to Director rufus:8101
799 1000 OK: rufus-dir Version: 1.26 (4 October 2002)
804 it will then print something like:
808 Using default Catalog name=BackupDB DB=bacula
809 The defined Storage resources are:
812 Select Storage resource (1-2): 1
816 I select the autochanger (1), and it prints:
820 Enter new Volume name: TestVolume1
821 Enter slot (0 for none): 1
825 where I entered {\bf TestVolume1} for the tape name, and slot {\bf 1} for the
833 Select the Pool (1-2): 1
837 I select the Default pool. This will be automatically done if you only have a
838 single pool, then Bacula will proceed to unload any loaded volume, load the
839 volume in slot 1 and label it. In this example, nothing was in the drive, so
844 Connecting to Storage daemon Autochanger at localhost:9103 ...
845 Sending label command ...
846 3903 Issuing autochanger "load slot 1" command.
847 3000 OK label. Volume=TestVolume1 Device=/dev/nst0
848 Media record for Volume=TestVolume1 successfully created.
849 Requesting mount Autochanger ...
850 3001 Device /dev/nst0 is mounted with Volume TestVolume1
856 You may then proceed to label the other volumes. The messages will change
857 slightly because Bacula will unload the volume (just labeled TestVolume1)
858 before loading the next volume to be labeled.
860 Once all your Volumes are labeled, Bacula will automatically load them as they
863 To "see" how you have labeled your Volumes, simply enter the {\bf list
864 volumes} command from the Console program, which should print something like
870 Using default Catalog name=BackupDB DB=bacula
874 Select the Pool (1-2): 1
875 +-------+----------+--------+---------+-------+--------+----------+-------+------+
876 | MedId | VolName | MedTyp | VolStat | Bites | LstWrt | VolReten | Recyc | Slot |
877 +-------+----------+--------+---------+-------+--------+----------+-------+------+
878 | 1 | TestVol1 | DDS-4 | Append | 0 | 0 | 30672000 | 0 | 1 |
879 | 2 | TestVol2 | DDS-4 | Append | 0 | 0 | 30672000 | 0 | 2 |
880 | 3 | TestVol3 | DDS-4 | Append | 0 | 0 | 30672000 | 0 | 3 |
882 +-------+----------+--------+---------+-------+--------+----------+-------+------+
888 \subsection*{Barcode Support}
889 \index[general]{Support!Barcode }
890 \index[general]{Barcode Support }
891 \addcontentsline{toc}{subsection}{Barcode Support}
893 Bacula provides barcode support with two Console commands, {\bf label
894 barcodes} and {\bf update slots}.
896 The {\bf label barcodes} will cause Bacula to read the barcodes of all the
897 cassettes that are currently installed in the magazine (cassette holder) using
898 the {\bf mtx-changer} {\bf list} command. Each cassette is mounted in turn and
899 labeled with the same Volume name as the barcode.
901 The {\bf update slots} command will first obtain the list of cassettes and
902 their barcodes from {\bf mtx-changer}. Then it will find each volume in turn
903 in the catalog database corresponding to the barcodes and set its Slot to
904 correspond to the value just read. If the Volume is not in the catalog, then
905 nothing will be done. This command is useful for synchronizing Bacula with the
906 current magazine in case you have changed magazines or in case you have moved
907 cassettes from one slot to another.
909 The {\bf Cleaning Prefix} statement can be used in the Pool resource to define
910 a Volume name prefix, which if it matches that of the Volume (barcode) will
911 cause that Volume to be marked with a VolStatus of {\bf Cleaning}. This will
912 prevent Bacula from attempting to write on the Volume.
916 \subsection*{Bacula Autochanger Interface}
917 \index[general]{Interface!Bacula Autochanger }
918 \index[general]{Bacula Autochanger Interface }
919 \addcontentsline{toc}{subsection}{Bacula Autochanger Interface}
921 Bacula calls the autochanger script that you specify on the {\bf Changer
922 Device} statement. Normally this script will be the {\bf mtx-changer} script
923 that we can provide, but it can in fact be any program. The only requirements
924 are that the "commands" that Bacula uses are {\bf loaded}, {\bf load}, {\bf
925 unload}, {\bf list}, and {\bf slots}. In addition,
926 each of those commands must return the information in the precise format as
931 - Currently the changer commands used are:
932 loaded -- returns number of the slot that is loaded, base 1,
933 in the drive or 0 if the drive is empty.
934 load -- loads a specified slot (note, some autochangers
935 require a 30 second pause after this command) into
937 unload -- unloads the device (returns cassette to its slot).
938 list -- returns one line for each cassette in the autochanger
939 in the format <slot>:<barcode>. Where
940 the {\bf slot} is the non-zero integer representing
941 the slot number, and {\bf barcode} is the barcode
942 associated with the cassette if it exists and if you
943 autoloader supports barcodes. Otherwise the barcode
945 slots -- returns total number of slots in the autochanger.
949 Bacula checks the exit status of the program called, and if it is zero, the
950 data is accepted. If the exit status is non-zero, Bacula ignores any
951 information returned and treats the drive as if it is not an autochanger.