4 \section*{Basic Volume Management}
5 \label{_ChapterStart39}
6 \index[general]{Basic Volume Management}
7 \index[general]{Management!Basic Volume}
8 \index[general]{Disk Volumes}
9 \addcontentsline{toc}{section}{Basic Volume Management}
11 This chapter presents most all the features needed to do Volume management.
12 Most of the concepts apply equally well to both tape and disk Volumes.
13 However, the chapter was originally written to explain backing up to disk, so
14 you will see it is slanted in that direction, but all the directives
15 presented here apply equally well whether your volume is disk or tape.
17 If you have a lot of hard disk storage or you absolutely must have your
18 backups run within a small time window, you may want to direct Bacula to
19 backup to disk Volumes rather than tape Volumes. This chapter is intended to
20 give you some of the options that are available to you so that you can manage
21 either disk or tape volumes.
24 \subsection*{Key Concepts and Resource Records}
25 \index[general]{Key Concepts and Resource Records }
26 \index[general]{Records!Key Concepts and Resource }
27 \addcontentsline{toc}{subsection}{Key Concepts and Resource Records}
29 Getting Bacula to write to disk rather than tape in the simplest case is
30 rather easy. In the Storage daemon's configuration file, you simply define an
31 {\bf Archive Device} to be a directory. For example, if you want your disk
32 backups to go into the directory {\bf /home/bacula/backups}, you could use the
40 Archive Device = /home/bacula/backups
49 Assuming you have the appropriate {\bf Storage} resource in your Director's
50 configuration file that references the above Device resource,
64 Bacula will then write the archive to the file {\bf
65 /home/bacula/backups/\lt{}volume-name\gt{}} where \lt{}volume-name\gt{} is the
66 volume name of a Volume defined in the Pool. For example, if you have labeled
67 a Volume named {\bf Vol001}, Bacula will write to the file {\bf
68 /home/bacula/backups/Vol001}. Although you can later move the archive file to
69 another directory, you should not rename it or it will become unreadable by
70 Bacula. This is because each archive has the filename as part of the internal
71 label, and the internal label must agree with the system filename before
74 Although this is quite simple, there are a number of problems. The first is
75 that unless you specify otherwise, Bacula will always write to the same volume
76 until you run out of disk space. This problem is addressed below.
78 In addition, if you want to use concurrent jobs that write to several
79 different volumes at the same time, you will need to understand a number
80 of other details. An example of such a configuration is given
81 at the end of this chapter under \ilink{Concurrent Disk
82 Jobs}{ConcurrentDiskJobs}.
84 \subsubsection*{Pool Options to Limit the Volume Usage}
85 \index[general]{Usage!Pool Options to Limit the Volume }
86 \index[general]{Pool Options to Limit the Volume Usage }
87 \addcontentsline{toc}{subsubsection}{Pool Options to Limit the Volume Usage}
89 Some of the options you have, all of which are specified in the Pool record,
93 \item To write each Volume only once (i.e. one Job per Volume or file in this
96 {\bf UseVolumeOnce = yes}.
98 \item To write nnn Jobs to each Volume, use:
100 {\bf Maximum Volume Jobs = nnn}.
102 \item To limit the maximum size of each Volume, use:
104 {\bf Maximum Volume Bytes = mmmm}.
106 Note, if you use disk volumes, with all versions up to and including
107 1.39.28, you should probably limit the Volume size to some reasonable
108 value such as say 5GB. This is because during a restore, Bacula is
109 currently unable to seek to the proper place in a disk volume to restore
110 a file, which means that it must read all records up to where the
111 restore begins. If your Volumes are 50GB, reading half or more of the
112 volume could take quite a bit of time. Also, if you ever have a partial
113 hard disk failure, you are more likely to be able to recover more data
114 if they are in smaller Volumes.
116 \item To limit the use time (i.e. write the Volume for a maximum of five days),
119 {\bf Volume Use Duration = ttt}.
122 Note that although you probably would not want to limit the number of bytes on
123 a tape as you would on a disk Volume, the other options can be very useful in
124 limiting the time Bacula will use a particular Volume (be it tape or disk).
125 For example, the above directives can allow you to ensure that you rotate
126 through a set of daily Volumes if you wish.
128 As mentioned above, each of those directives is specified in the Pool or
129 Pools that you use for your Volumes. In the case of {\bf Maximum Volume Job},
130 {\bf Maximum Volume Bytes}, and {\bf Volume Use Duration}, you can actually
131 specify the desired value on a Volume by Volume basis. The value specified in
132 the Pool record becomes the default when labeling new Volumes. Once a Volume
133 has been created, it gets its own copy of the Pool defaults, and subsequently
134 changing the Pool will have no effect on existing Volumes. You can either
135 manually change the Volume values, or refresh them from the Pool defaults using
136 the {\bf update volume} command in the Console. As an example
137 of the use of one of the above, suppose your Pool resource contains:
144 Volume Use Duration = 23h
149 then if you run a backup once a day (every 24 hours), Bacula will use a new
150 Volume for each backup, because each Volume it writes can only be used for 23 hours
151 after the first write. Note, setting the use duration to 23 hours is not a very
152 good solution for tapes unless you have someone on-site during the weekends,
153 because Bacula will want a new Volume and no one will be present to mount it,
154 so no weekend backups will be done until Monday morning.
156 \label{AutomaticLabeling}
157 \subsubsection*{Automatic Volume Labeling}
158 \index[general]{Automatic Volume Labeling }
159 \index[general]{Labeling!Automatic Volume }
160 \addcontentsline{toc}{subsubsection}{Automatic Volume Labeling}
162 Use of the above records brings up another problem -- that of labeling your
163 Volumes. For automated disk backup, you can either manually label each of your
164 Volumes, or you can have Bacula automatically label new Volumes when they are
165 needed. While, the automatic Volume labeling in version 1.30 and prior is a
166 bit simplistic, but it does allow for automation, the features added in
167 version 1.31 permit automatic creation of a wide variety of labels including
168 information from environment variables and special Bacula Counter variables.
169 In version 1.37 and later, it is probably much better to use Python scripting
170 and the NewVolume event since generating Volume labels in a Python script is
171 much easier than trying to figure out Counter variables. See the
172 \ilink{Python Scripting}{_ChapterStart60} chapter of this manual for more
175 Please note that automatic Volume labeling can also be used with tapes, but
176 it is not nearly so practical since the tapes must be pre-mounted. This
177 requires some user interaction. Automatic labeling from templates does NOT
178 work with autochangers since Bacula will not access unknown slots. There
179 are several methods of labeling all volumes in an autochanger magazine.
180 For more information on this, please see the \ilink{
181 Autochanger}{_ChapterStart18} chapter of this manual.
183 Automatic Volume labeling is enabled by making a change to both the Pool
184 resource (Director) and to the Device resource (Storage daemon) shown above.
185 In the case of the Pool resource, you must provide Bacula with a label format
186 that it will use to create new names. In the simplest form, the label format
187 is simply the Volume name, to which Bacula will append a four digit number.
188 This number starts at 0001 and is incremented for each Volume the pool
189 contains. Thus if you modify your Pool resource to be:
196 Volume Use Duration = 23h
202 Bacula will create Volume names Vol0001, Vol0002, and so on when new Volumes
203 are needed. Much more complex and elaborate labels can be created using
204 variable expansion defined in the
205 \ilink{Variable Expansion}{_ChapterStart50} chapter of this manual.
207 The second change that is necessary to make automatic labeling work is to give
208 the Storage daemon permission to automatically label Volumes. Do so by adding
209 {\bf LabelMedia = yes} to the Device resource as follows:
216 Archive Device = /home/bacula/backups
218 AutomaticMount = yes;
226 You can find more details of the {\bf Label Format} Pool record in
227 \ilink{Label Format}{Label} description of the Pool resource
231 \subsubsection*{Restricting the Number of Volumes and Recycling}
232 \index[general]{Recycling!Restricting the Number of Volumes and }
233 \index[general]{Restricting the Number of Volumes and Recycling }
234 \addcontentsline{toc}{subsubsection}{Restricting the Number of Volumes and
237 Automatic labeling discussed above brings up the problem of Volume management.
238 With the above scheme, a new Volume will be created every day. If you have not
239 specified Retention periods, your Catalog will continue to fill keeping track
240 of all the files Bacula has backed up, and this procedure will create one new
241 archive file (Volume) every day.
243 The tools Bacula gives you to help automatically manage these problems are the
247 \item Catalog file record retention periods, the
248 \ilink{File Retention = ttt}{FileRetention} record in the Client
250 \item Catalog job record retention periods, the
251 \ilink{Job Retention = ttt}{JobRetention} record in the Client
254 \ilink{ AutoPrune = yes}{AutoPrune} record in the Client resource
255 to permit application of the above two retention periods.
257 \ilink{ Volume Retention = ttt}{VolRetention} record in the Pool
260 \ilink{ AutoPrune = yes}{PoolAutoPrune} record in the Pool
261 resource to permit application of the Volume retention period.
263 \ilink{ Recycle = yes}{PoolRecycle} record in the Pool resource
264 to permit automatic recycling of Volumes whose Volume retention period has
267 \ilink{ Recycle Oldest Volume = yes}{RecycleOldest} record in the
268 Pool resource tells Bacula to Prune the oldest volume in the Pool, and if all
269 files were pruned to recycle this volume and use it.
271 \ilink{ Recycle Current Volume = yes}{RecycleCurrent} record in
272 the Pool resource tells Bacula to Prune the currently mounted volume in the
273 Pool, and if all files were pruned to recycle this volume and use it.
275 \ilink{ Purge Oldest Volume = yes}{PurgeOldest} record in the
276 Pool resource permits a forced recycling of the oldest Volume when a new one
277 is needed. {\bf N.B. This record ignores retention periods! We highly
278 recommend not to use this record, but instead use Recycle Oldest Volume}
280 \ilink{ Maximum Volumes = nnn}{MaxVolumes} record in the Pool
281 resource to limit the number of Volumes that can be created.
284 The first three records (File Retention, Job Retention, and AutoPrune)
285 determine the amount of time that Job and File records will remain in your
286 Catalog, and they are discussed in detail in the
287 \ilink{Automatic Volume Recycling}{_ChapterStart22} chapter of
290 Volume Retention, AutoPrune, and Recycle determine how long Bacula will keep
291 your Volumes before reusing them, and they are also discussed in detail in the
292 \ilink{Automatic Volume Recycling}{_ChapterStart22} chapter of
295 The Maximum Volumes record can also be used in conjunction with the Volume
296 Retention period to limit the total number of archive Volumes (files) that
297 Bacula will create. By setting an appropriate Volume Retention period, a
298 Volume will be purged just before it is needed and thus Bacula can cycle
299 through a fixed set of Volumes. Cycling through a fixed set of Volumes can
300 also be done by setting {\bf Recycle Oldest Volume = yes} or {\bf Recycle
301 Current Volume = yes}. In this case, when Bacula needs a new Volume, it will
302 prune the specified volume.
304 \label{ConcurrentDiskJobs}
305 \subsection*{Concurrent Disk Jobs}
306 \index[general]{Concurrent Disk Jobs}
307 \addcontentsline{toc}{subsection}{Concurrent Disk Jobs}
308 Above, we discussed how you could have a single device named {\bf
309 FileBackup} that writes to volumes in {\bf /home/bacula/backups}.
310 You can, in fact, run multiple concurrent jobs using the
311 Storage definition given with this example, and all the jobs will
312 simultaneously write into the Volume that is being written.
314 Now suppose you want to use multiple Pools, which means multiple
315 Volumes, or suppose you want each client to have its own Volume
316 and perhaps its own directory such as {\bf /home/bacula/client1}
317 and {\bf /home/bacula/client2} ... With the single Storage and Device
318 definition above, neither of these two is possible. Why? Because
319 Bacula disk storage follows the same rules as tape devices. Only
320 one Volume can be mounted on any Device at any time. If you want
321 to simultaneously write multiple Volumes, you will need multiple
322 Device resources in your bacula-sd.conf file, and thus multiple
323 Storage resources in your bacula-dir.conf.
325 OK, so now you should understand that you need multiple Device definitions
326 in the case of different directories or different Pools, but you also
327 need to know that the catalog data that Bacula keeps contains only
328 the Media Type and not the specific storage device. This permits a tape
329 for example to be re-read on any compatible tape drive. The compatibility
330 being determined by the Media Type. The same applies to disk storage.
331 Since a volume that is written by a Device in say directory {\bf
332 /home/bacula/backups} cannot be read by a Device with an Archive Device
333 definition of {\bf /home/bacula/client1}, you will not be able to
334 restore all your files if you give both those devices
335 {\bf Media Type = File}. During the restore, Bacula will simply choose
336 the first available device, which may not be the correct one. If this
337 is confusing, just remember that the Directory has only the Media Type
338 and the Volume name. It does not know the {\bf Archive Device} (or the
339 full path) that is specified in the Storage daemon. Thus you must
340 explicitly tie your Volumes to the correct Device by using the Media Type.
342 The example shown below shows a case where there are two clients, each
343 using its own Pool and storing their Volumes in different directories.
347 \subsection*{An Example}
348 \index[general]{Example }
349 \addcontentsline{toc}{subsection}{Example}
351 The following example is not very practical, but can be used to demonstrate
352 the proof of concept in a relatively short period of time. The example
353 consists of a two clients that are backed up to a set of 12 archive files
354 (Volumes) for each client into different directories on the Storage
355 machine. Each Volume is used (written) only once, and there are four Full
356 saves done every hour (so the whole thing cycles around after three hours).
358 What is key here is that each physical device on the Storage daemon
359 has a different Media Type. This allows the Director to choose the
360 correct device for restores ...
362 The Director's configuration file is as follows:
368 QueryFile = "~/bacula/bin/query.sql"
369 PidDirectory = "~/bacula/working"
370 WorkingDirectory = "~/bacula/working"
371 Password = dir_password
375 Run = Level=Full hourly at 0:05
376 Run = Level=Full hourly at 0:20
377 Run = Level=Full hourly at 0:35
378 Run = Level=Full hourly at 0:50
381 Name = "RecycleExample"
385 FileSet= "Example FileSet"
387 Storage = FileStorage
389 Schedule = FourPerHour
393 Name = "RecycleExample2"
397 FileSet= "Example FileSet"
399 Storage = FileStorage1
401 Schedule = FourPerHour
405 Name = "Example FileSet"
406 Include = compression=GZIP signature=SHA1 {
407 /home/kern/bacula/bin
414 Password = client_password
421 Password = client1_password
427 Password = local_storage_password
435 Password = local_storage_password
442 dbname = bacula; user = bacula; password = ""
450 Use Volume Once = yes
452 LabelFormat = "Recycle-"
461 Use Volume Once = yes
463 LabelFormat = "Recycle1-"
473 and the Storage daemon's configuration file is:
479 WorkingDirectory = "~/bacula/working"
480 Pid Directory = "~/bacula/working"
481 MaximumConcurrentJobs = 10
485 Password = local_storage_password
490 Archive Device = /home/bacula/backups
493 AutomaticMount = yes;
501 Archive Device = /home/bacula/backups1
504 AutomaticMount = yes;
511 director = my-dir = all
516 With a little bit of work, you can change the above example into a weekly or
517 monthly cycle (take care about the amount of archive disk space used).
519 \label{MultipleDisks}
520 \subsection*{Backing up to Multiple Disks}
521 \index[general]{Disks!Backing up to Multiple }
522 \index[general]{Backing up to Multiple Disks }
523 \addcontentsline{toc}{subsection}{Backing up to Multiple Disks}
525 Bacula can, of course, use multiple disks, but in general, each disk must be a
526 separate Device specification in the Storage daemon's conf file, and you must
527 then select what clients to backup to each disk. You will also want to
528 give each Device specification a different Media Type so that during
529 a restore, Bacula will be able to find the appropriate drive.
531 The situation is a bit more complicated if you want to treat two different
532 physical disk drives (or partitions) logically as a single drive, which
533 Bacula does not directly support. However, it is possible to back up your
534 data to multiple disks as if they were a single drive by linking the
535 Volumes from the first disk to the second disk.
537 For example, assume that you have two disks named {\bf /disk1} and {\bf
538 /disk2}. If you then create a standard Storage daemon Device resource for
539 backing up to the first disk, it will look like the following:
546 Archive Device = /disk1
549 AutomaticMount = yes;
556 Since there is no way to get the above Device resource to reference both {\bf
557 /disk1} and {\bf /disk2} we do it by pre-creating Volumes on /disk2 with the
562 ln -s /disk2/Disk2-vol001 /disk1/Disk2-vol001
563 ln -s /disk2/Disk2-vol002 /disk1/Disk2-vol002
564 ln -s /disk2/Disk2-vol003 /disk1/Disk2-vol003
569 At this point, you can label the Volumes as Volume {\bf Disk2-vol001}, {\bf
570 Disk2-vol002}, ... and Bacula will use them as if they were on /disk1 but
571 actually write the data to /disk2. The only minor inconvenience with this
572 method is that you must explicitly name the disks and cannot use automatic
573 labeling unless you arrange to have the labels exactly match the links you
576 An important thing to know is that Bacula treats disks like tape drives
577 as much as it can. This means that you can only have a single Volume
578 mounted at one time on a disk as defined in your Device resource in
579 the Storage daemon's conf file. You can have multiple concurrent
580 jobs running that all write to the one Volume that is being used, but
581 if you want to have multiple concurrent jobs that are writing to
582 separate disks drives (or partitions), you will need to define
583 separate Device resources for each one, exactly as you would do for
584 two different tape drives. There is one fundamental difference, however.
585 The Volumes that you create on the two drives cannot be easily exchanged
586 as they can for a tape drive, because they are physically resident (already
587 mounted in a sense) on the particular drive. As a consequence, you will
588 probably want to give them different Media Types so that Bacula can
589 distinguish what Device resource to use during a restore.
590 An example would be the following:
597 Archive Device = /disk1
600 AutomaticMount = yes;
608 Archive Device = /disk2
611 AutomaticMount = yes;
618 With the above device definitions, you can run two concurrent
619 jobs each writing at the same time, one to {\bf /disk2} and the
620 other to {\bf /disk2}. The fact that you have given them different
621 Media Types will allow Bacula to quickly choose the correct
622 Storage resource in the Director when doing a restore.
624 \label{MultipleClients}
625 \subsection*{Considerations for Multiple Clients}
626 \index[general]{Clients!Considerations for Multiple }
627 \index[general]{Multiple Clients}
628 \addcontentsline{toc}{subsection}{Considerations for Multiple Clients}
630 If we take the above example and add a second Client, here are a few
634 \item Although the second client can write to the same set of Volumes, you
635 will probably want to write to a different set.
636 \item You can write to a different set of Volumes by defining a second Pool,
637 which has a different name and a different {\bf LabelFormat}.
638 \item If you wish the Volumes for the second client to go into a different
639 directory (perhaps even on a different filesystem to spread the load), you
640 would do so by defining a second Device resource in the Storage daemon. The
641 {\bf Name} must be different, and the {\bf Archive Device} could be
642 different. To ensure that Volumes are never mixed from one pool to another,
643 you might also define a different MediaType (e.g. {\bf File1}).
646 In this example, we have two clients, each with a different Pool and a
647 different number of archive files retained. They also write to different
648 directories with different Volume labeling.
650 The Director's configuration file is as follows:
656 QueryFile = "~/bacula/bin/query.sql"
657 PidDirectory = "~/bacula/working"
658 WorkingDirectory = "~/bacula/working"
659 Password = dir_password
661 # Basic weekly schedule
663 Name = "WeeklySchedule"
664 Run = Level=Full fri at 1:30
665 Run = Level=Incremental sat-thu at 1:30
668 Name = "Example FileSet"
669 Include = compression=GZIP signature=SHA1 {
670 /home/kern/bacula/bin
674 Name = "Backup-client1"
678 FileSet= "Example FileSet"
682 Schedule = "WeeklySchedule"
685 Name = "Backup-client2"
689 FileSet= "Example FileSet"
693 Schedule = "WeeklySchedule"
699 Password = client1_password
706 Password = client2_password
708 # Two Storage definitions with different Media Types
709 # permits different directories
713 Password = local_storage_password
720 Password = local_storage_password
726 dbname = bacula; user = bacula; password = ""
732 # Two pools permits different cycling periods and Volume names
733 # Cycle through 15 Volumes (two weeks)
736 Use Volume Once = yes
738 LabelFormat = "Client1-"
740 VolumeRetention = 13d
744 # Cycle through 8 Volumes (1 week)
747 Use Volume Once = yes
749 LabelFormat = "Client2-"
758 and the Storage daemon's configuration file is:
764 WorkingDirectory = "~/bacula/working"
765 Pid Directory = "~/bacula/working"
766 MaximumConcurrentJobs = 10
770 Password = local_storage_password
772 # Archive directory for Client1
776 Archive Device = /home/bacula/client1
779 AutomaticMount = yes;
783 # Archive directory for Client2
787 Archive Device = /home/bacula/client2
790 AutomaticMount = yes;
796 director = my-dir = all