4 \chapter{Basic Volume Management}
6 \index[general]{Basic Volume Management}
7 \index[general]{Management!Basic Volume}
8 \index[general]{Disk Volumes}
10 This chapter presents most all the features needed to do Volume management.
11 Most of the concepts apply equally well to both tape and disk Volumes.
12 However, the chapter was originally written to explain backing up to disk, so
13 you will see it is slanted in that direction, but all the directives
14 presented here apply equally well whether your volume is disk or tape.
16 If you have a lot of hard disk storage or you absolutely must have your
17 backups run within a small time window, you may want to direct Bacula to
18 backup to disk Volumes rather than tape Volumes. This chapter is intended to
19 give you some of the options that are available to you so that you can manage
20 either disk or tape volumes.
23 \section{Key Concepts and Resource Records}
24 \index[general]{Key Concepts and Resource Records }
25 \index[general]{Records!Key Concepts and Resource }
27 Getting Bacula to write to disk rather than tape in the simplest case is
28 rather easy. In the Storage daemon's configuration file, you simply define an
29 {\bf Archive Device} to be a directory. For example, if you want your disk
30 backups to go into the directory {\bf /home/bacula/backups}, you could use the
38 Archive Device = /home/bacula/backups
47 Assuming you have the appropriate {\bf Storage} resource in your Director's
48 configuration file that references the above Device resource,
62 Bacula will then write the archive to the file {\bf
63 /home/bacula/backups/\lt{}volume-name\gt{}} where \lt{}volume-name\gt{} is the
64 volume name of a Volume defined in the Pool. For example, if you have labeled
65 a Volume named {\bf Vol001}, Bacula will write to the file {\bf
66 /home/bacula/backups/Vol001}. Although you can later move the archive file to
67 another directory, you should not rename it or it will become unreadable by
68 Bacula. This is because each archive has the filename as part of the internal
69 label, and the internal label must agree with the system filename before
72 Although this is quite simple, there are a number of problems. The first is
73 that unless you specify otherwise, Bacula will always write to the same volume
74 until you run out of disk space. This problem is addressed below.
76 In addition, if you want to use concurrent jobs that write to several
77 different volumes at the same time, you will need to understand a number
78 of other details. An example of such a configuration is given
79 at the end of this chapter under \ilink{Concurrent Disk Jobs}{ConcurrentDiskJobs}.
81 \subsection{Pool Options to Limit the Volume Usage}
82 \index[general]{Usage!Pool Options to Limit the Volume }
83 \index[general]{Pool Options to Limit the Volume Usage }
85 Some of the options you have, all of which are specified in the Pool record,
89 \item To write each Volume only once (i.e. one Job per Volume or file in this
92 {\bf UseVolumeOnce = yes}.
94 \item To write nnn Jobs to each Volume, use:
96 {\bf Maximum Volume Jobs = nnn}.
98 \item To limit the maximum size of each Volume, use:
100 {\bf Maximum Volume Bytes = mmmm}.
102 Note, if you use disk volumes, with all versions up to and including
103 1.39.28, you should probably limit the Volume size to some reasonable
104 value such as say 5GB. This is because during a restore, Bacula is
105 currently unable to seek to the proper place in a disk volume to restore
106 a file, which means that it must read all records up to where the
107 restore begins. If your Volumes are 50GB, reading half or more of the
108 volume could take quite a bit of time. Also, if you ever have a partial
109 hard disk failure, you are more likely to be able to recover more data
110 if they are in smaller Volumes.
112 \item To limit the use time (i.e. write the Volume for a maximum of five days),
115 {\bf Volume Use Duration = ttt}.
118 Note that although you probably would not want to limit the number of bytes on
119 a tape as you would on a disk Volume, the other options can be very useful in
120 limiting the time Bacula will use a particular Volume (be it tape or disk).
121 For example, the above directives can allow you to ensure that you rotate
122 through a set of daily Volumes if you wish.
124 As mentioned above, each of those directives is specified in the Pool or
125 Pools that you use for your Volumes. In the case of {\bf Maximum Volume Job},
126 {\bf Maximum Volume Bytes}, and {\bf Volume Use Duration}, you can actually
127 specify the desired value on a Volume by Volume basis. The value specified in
128 the Pool record becomes the default when labeling new Volumes. Once a Volume
129 has been created, it gets its own copy of the Pool defaults, and subsequently
130 changing the Pool will have no effect on existing Volumes. You can either
131 manually change the Volume values, or refresh them from the Pool defaults using
132 the {\bf update volume} command in the Console. As an example
133 of the use of one of the above, suppose your Pool resource contains:
140 Volume Use Duration = 23h
145 then if you run a backup once a day (every 24 hours), Bacula will use a new
146 Volume for each backup, because each Volume it writes can only be used for 23 hours
147 after the first write. Note, setting the use duration to 23 hours is not a very
148 good solution for tapes unless you have someone on-site during the weekends,
149 because Bacula will want a new Volume and no one will be present to mount it,
150 so no weekend backups will be done until Monday morning.
152 \label{AutomaticLabeling}
153 \subsection{Automatic Volume Labeling}
154 \index[general]{Automatic Volume Labeling }
155 \index[general]{Labeling!Automatic Volume }
157 Use of the above records brings up another problem -- that of labeling your
158 Volumes. For automated disk backup, you can either manually label each of your
159 Volumes, or you can have Bacula automatically label new Volumes when they are
160 needed. While, the automatic Volume labeling in version 1.30 and prior is a
161 bit simplistic, but it does allow for automation, the features added in
162 version 1.31 permit automatic creation of a wide variety of labels including
163 information from environment variables and special Bacula Counter variables.
164 In version 1.37 and later, it is probably much better to use Python scripting
165 and the NewVolume event since generating Volume labels in a Python script is
166 much easier than trying to figure out Counter variables. See the
167 \borgxrlink{Python Scripting}{PythonChapter}{misc}{chapter} of the \miscman{}
170 Please note that automatic Volume labeling can also be used with tapes, but
171 it is not nearly so practical since the tapes must be pre-mounted. This
172 requires some user interaction. Automatic labeling from templates does NOT
173 work with autochangers since Bacula will not access unknown slots. There
174 are several methods of labeling all volumes in an autochanger magazine.
175 For more information on this, please see the \ilink{
176 Autochanger}{AutochangersChapter} chapter of this manual.
178 Automatic Volume labeling is enabled by making a change to both the Pool
179 resource (Director) and to the Device resource (Storage daemon) shown above.
180 In the case of the Pool resource, you must provide Bacula with a label format
181 that it will use to create new names. In the simplest form, the label format
182 is simply the Volume name, to which Bacula will append a four digit number.
183 This number starts at 0001 and is incremented for each Volume the catalog
184 contains. Thus if you modify your Pool resource to be:
191 Volume Use Duration = 23h
197 Bacula will create Volume names Vol0001, Vol0002, and so on when new Volumes
198 are needed. Much more complex and elaborate labels can be created using
199 variable expansion defined in the
200 \ilink{Variable Expansion}{VarsChapter} chapter of this manual.
202 The second change that is necessary to make automatic labeling work is to give
203 the Storage daemon permission to automatically label Volumes. Do so by adding
204 {\bf LabelMedia = yes} to the Device resource as follows:
211 Archive Device = /home/bacula/backups
213 AutomaticMount = yes;
221 You can find more details of the {\bf Label Format} Pool record in
222 \ilink{Label Format}{Label} description of the Pool resource
226 \subsection{Restricting the Number of Volumes and Recycling}
227 \index[general]{Recycling!Restricting the Number of Volumes and Recycling}
228 \index[general]{Restricting the Number of Volumes and Recycling}
230 Automatic labeling discussed above brings up the problem of Volume management.
231 With the above scheme, a new Volume will be created every day. If you have not
232 specified Retention periods, your Catalog will continue to fill keeping track
233 of all the files Bacula has backed up, and this procedure will create one new
234 archive file (Volume) every day.
236 The tools Bacula gives you to help automatically manage these problems are the
240 \item Catalog file record retention periods, the
241 \ilink{File Retention = ttt}{FileRetention} record in the Client
243 \item Catalog job record retention periods, the
244 \ilink{Job Retention = ttt}{JobRetention} record in the Client
247 \ilink{ AutoPrune = yes}{AutoPrune} record in the Client resource
248 to permit application of the above two retention periods.
250 \ilink{ Volume Retention = ttt}{VolRetention} record in the Pool
253 \ilink{ AutoPrune = yes}{PoolAutoPrune} record in the Pool
254 resource to permit application of the Volume retention period.
256 \ilink{ Recycle = yes}{PoolRecycle} record in the Pool resource
257 to permit automatic recycling of Volumes whose Volume retention period has
260 \ilink{ Recycle Oldest Volume = yes}{RecycleOldest} record in the
261 Pool resource tells Bacula to Prune the oldest volume in the Pool, and if all
262 files were pruned to recycle this volume and use it.
264 \ilink{ Recycle Current Volume = yes}{RecycleCurrent} record in
265 the Pool resource tells Bacula to Prune the currently mounted volume in the
266 Pool, and if all files were pruned to recycle this volume and use it.
268 \ilink{ Purge Oldest Volume = yes}{PurgeOldest} record in the
269 Pool resource permits a forced recycling of the oldest Volume when a new one
270 is needed. {\bf N.B. This record ignores retention periods! We highly
271 recommend not to use this record, but instead use Recycle Oldest Volume}
273 \ilink{ Maximum Volumes = nnn}{MaxVolumes} record in the Pool
274 resource to limit the number of Volumes that can be created.
277 The first three records (File Retention, Job Retention, and AutoPrune)
278 determine the amount of time that Job and File records will remain in your
279 Catalog, and they are discussed in detail in the
280 \ilink{Automatic Volume Recycling}{RecyclingChapter} chapter of
283 Volume Retention, AutoPrune, and Recycle determine how long Bacula will keep
284 your Volumes before reusing them, and they are also discussed in detail in the
285 \ilink{Automatic Volume Recycling}{RecyclingChapter} chapter of
288 The Maximum Volumes record can also be used in conjunction with the Volume
289 Retention period to limit the total number of archive Volumes (files) that
290 Bacula will create. By setting an appropriate Volume Retention period, a
291 Volume will be purged just before it is needed and thus Bacula can cycle
292 through a fixed set of Volumes. Cycling through a fixed set of Volumes can
293 also be done by setting {\bf Recycle Oldest Volume = yes} or {\bf Recycle
294 Current Volume = yes}. In this case, when Bacula needs a new Volume, it will
295 prune the specified volume.
297 \label{ConcurrentDiskJobs}
298 \section{Concurrent Disk Jobs}
299 \index[general]{Concurrent Disk Jobs}
300 Above, we discussed how you could have a single device named {\bf
301 FileBackup} that writes to volumes in {\bf /home/bacula/backups}.
302 You can, in fact, run multiple concurrent jobs using the
303 Storage definition given with this example, and all the jobs will
304 simultaneously write into the Volume that is being written.
306 Now suppose you want to use multiple Pools, which means multiple
307 Volumes, or suppose you want each client to have its own Volume
308 and perhaps its own directory such as {\bf /home/bacula/client1}
309 and {\bf /home/bacula/client2} ... With the single Storage and Device
310 definition above, neither of these two is possible. Why? Because
311 Bacula disk storage follows the same rules as tape devices. Only
312 one Volume can be mounted on any Device at any time. If you want
313 to simultaneously write multiple Volumes, you will need multiple
314 Device resources in your bacula-sd.conf file, and thus multiple
315 Storage resources in your bacula-dir.conf.
317 OK, so now you should understand that you need multiple Device definitions
318 in the case of different directories or different Pools, but you also
319 need to know that the catalog data that Bacula keeps contains only
320 the Media Type and not the specific storage device. This permits a tape
321 for example to be re-read on any compatible tape drive. The compatibility
322 being determined by the Media Type. The same applies to disk storage.
323 Since a volume that is written by a Device in say directory {\bf
324 /home/bacula/backups} cannot be read by a Device with an Archive Device
325 definition of {\bf /home/bacula/client1}, you will not be able to
326 restore all your files if you give both those devices
327 {\bf Media Type = File}. During the restore, Bacula will simply choose
328 the first available device, which may not be the correct one. If this
329 is confusing, just remember that the Directory has only the Media Type
330 and the Volume name. It does not know the {\bf Archive Device} (or the
331 full path) that is specified in the Storage daemon. Thus you must
332 explicitly tie your Volumes to the correct Device by using the Media Type.
334 The example shown below shows a case where there are two clients, each
335 using its own Pool and storing their Volumes in different directories.
340 \index[general]{Example }
342 The following example is not very practical, but can be used to demonstrate
343 the proof of concept in a relatively short period of time. The example
344 consists of a two clients that are backed up to a set of 12 archive files
345 (Volumes) for each client into different directories on the Storage
346 machine. Each Volume is used (written) only once, and there are four Full
347 saves done every hour (so the whole thing cycles around after three hours).
349 What is key here is that each physical device on the Storage daemon
350 has a different Media Type. This allows the Director to choose the
351 correct device for restores ...
353 The Director's configuration file is as follows:
359 QueryFile = "~/bacula/bin/query.sql"
360 PidDirectory = "~/bacula/working"
361 WorkingDirectory = "~/bacula/working"
362 Password = dir_password
366 Run = Level=Full hourly at 0:05
367 Run = Level=Full hourly at 0:20
368 Run = Level=Full hourly at 0:35
369 Run = Level=Full hourly at 0:50
372 Name = "RecycleExample"
376 FileSet= "Example FileSet"
378 Storage = FileStorage
380 Schedule = FourPerHour
384 Name = "RecycleExample2"
388 FileSet= "Example FileSet"
390 Storage = FileStorage1
392 Schedule = FourPerHour
396 Name = "Example FileSet"
402 File = /home/kern/bacula/bin
410 Password = client_password
417 Password = client1_password
423 Password = local_storage_password
431 Password = local_storage_password
438 dbname = bacula; user = bacula; password = ""
446 Use Volume Once = yes
448 LabelFormat = "Recycle-"
457 Use Volume Once = yes
459 LabelFormat = "Recycle1-"
469 and the Storage daemon's configuration file is:
475 WorkingDirectory = "~/bacula/working"
476 Pid Directory = "~/bacula/working"
477 MaximumConcurrentJobs = 10
481 Password = local_storage_password
486 Archive Device = /home/bacula/backups
489 AutomaticMount = yes;
497 Archive Device = /home/bacula/backups1
500 AutomaticMount = yes;
507 director = my-dir = all
512 With a little bit of work, you can change the above example into a weekly or
513 monthly cycle (take care about the amount of archive disk space used).
515 \label{MultipleDisks}
516 \section{Backing up to Multiple Disks}
517 \index[general]{Disks!Backing up to Multiple }
518 \index[general]{Backing up to Multiple Disks }
520 Bacula can, of course, use multiple disks, but in general, each disk must be a
521 separate Device specification in the Storage daemon's conf file, and you must
522 then select what clients to backup to each disk. You will also want to
523 give each Device specification a different Media Type so that during
524 a restore, Bacula will be able to find the appropriate drive.
526 The situation is a bit more complicated if you want to treat two different
527 physical disk drives (or partitions) logically as a single drive, which
528 Bacula does not directly support. However, it is possible to back up your
529 data to multiple disks as if they were a single drive by linking the
530 Volumes from the first disk to the second disk.
532 For example, assume that you have two disks named {\bf /disk1} and {\bf
533 /disk2}. If you then create a standard Storage daemon Device resource for
534 backing up to the first disk, it will look like the following:
541 Archive Device = /disk1
544 AutomaticMount = yes;
551 Since there is no way to get the above Device resource to reference both {\bf
552 /disk1} and {\bf /disk2} we do it by pre-creating Volumes on /disk2 with the
557 ln -s /disk2/Disk2-vol001 /disk1/Disk2-vol001
558 ln -s /disk2/Disk2-vol002 /disk1/Disk2-vol002
559 ln -s /disk2/Disk2-vol003 /disk1/Disk2-vol003
564 At this point, you can label the Volumes as Volume {\bf Disk2-vol001}, {\bf
565 Disk2-vol002}, ... and Bacula will use them as if they were on /disk1 but
566 actually write the data to /disk2. The only minor inconvenience with this
567 method is that you must explicitly name the disks and cannot use automatic
568 labeling unless you arrange to have the labels exactly match the links you
571 An important thing to know is that Bacula treats disks like tape drives
572 as much as it can. This means that you can only have a single Volume
573 mounted at one time on a disk as defined in your Device resource in
574 the Storage daemon's conf file. You can have multiple concurrent
575 jobs running that all write to the one Volume that is being used, but
576 if you want to have multiple concurrent jobs that are writing to
577 separate disks drives (or partitions), you will need to define
578 separate Device resources for each one, exactly as you would do for
579 two different tape drives. There is one fundamental difference, however.
580 The Volumes that you create on the two drives cannot be easily exchanged
581 as they can for a tape drive, because they are physically resident (already
582 mounted in a sense) on the particular drive. As a consequence, you will
583 probably want to give them different Media Types so that Bacula can
584 distinguish what Device resource to use during a restore.
585 An example would be the following:
592 Archive Device = /disk1
595 AutomaticMount = yes;
603 Archive Device = /disk2
606 AutomaticMount = yes;
613 With the above device definitions, you can run two concurrent
614 jobs each writing at the same time, one to {\bf /disk1} and the
615 other to {\bf /disk2}. The fact that you have given them different
616 Media Types will allow Bacula to quickly choose the correct
617 Storage resource in the Director when doing a restore.
619 \label{MultipleClients}
620 \section{Considerations for Multiple Clients}
621 \index[general]{Clients!Considerations for Multiple }
622 \index[general]{Multiple Clients}
624 If we take the above example and add a second Client, here are a few
628 \item Although the second client can write to the same set of Volumes, you
629 will probably want to write to a different set.
630 \item You can write to a different set of Volumes by defining a second Pool,
631 which has a different name and a different {\bf LabelFormat}.
632 \item If you wish the Volumes for the second client to go into a different
633 directory (perhaps even on a different filesystem to spread the load), you
634 would do so by defining a second Device resource in the Storage daemon. The
635 {\bf Name} must be different, and the {\bf Archive Device} could be
636 different. To ensure that Volumes are never mixed from one pool to another,
637 you might also define a different MediaType (e.g. {\bf File1}).
640 In this example, we have two clients, each with a different Pool and a
641 different number of archive files retained. They also write to different
642 directories with different Volume labeling.
644 The Director's configuration file is as follows:
650 QueryFile = "~/bacula/bin/query.sql"
651 PidDirectory = "~/bacula/working"
652 WorkingDirectory = "~/bacula/working"
653 Password = dir_password
655 # Basic weekly schedule
657 Name = "WeeklySchedule"
658 Run = Level=Full fri at 1:30
659 Run = Level=Incremental sat-thu at 1:30
662 Name = "Example FileSet"
668 File = /home/kern/bacula/bin
672 Name = "Backup-client1"
676 FileSet= "Example FileSet"
680 Schedule = "WeeklySchedule"
683 Name = "Backup-client2"
687 FileSet= "Example FileSet"
691 Schedule = "WeeklySchedule"
697 Password = client1_password
704 Password = client2_password
706 # Two Storage definitions with different Media Types
707 # permits different directories
711 Password = local_storage_password
718 Password = local_storage_password
724 dbname = bacula; user = bacula; password = ""
730 # Two pools permits different cycling periods and Volume names
731 # Cycle through 15 Volumes (two weeks)
734 Use Volume Once = yes
736 LabelFormat = "Client1-"
738 VolumeRetention = 13d
742 # Cycle through 8 Volumes (1 week)
745 Use Volume Once = yes
747 LabelFormat = "Client2-"
756 and the Storage daemon's configuration file is:
762 WorkingDirectory = "~/bacula/working"
763 Pid Directory = "~/bacula/working"
764 MaximumConcurrentJobs = 10
768 Password = local_storage_password
770 # Archive directory for Client1
774 Archive Device = /home/bacula/client1
777 AutomaticMount = yes;
781 # Archive directory for Client2
785 Archive Device = /home/bacula/client2
788 AutomaticMount = yes;
794 director = my-dir = all