This chapter presents most all the features needed to do Volume management. Most of the concepts apply equally well to both tape and disk Volumes. However, the chapter was originally written to explain backing up to disk, so you will see it is slanted in that direction, but that all the directives presented here apply equally well whether your volume is disk or tape.
If you have a lot of hard disk storage or you absolutely must have your backups run within a small time window, you may want to direct Bacula to backup to disk Volumes rather than tape Volumes. This chapter is intended to give you some of the options that are available to you so that you can manage either disk or tape volumes.
Getting Bacula to write to disk rather than tape in the simplest case is rather easy. In the Storage daemon's configuration file, you simply define an Archive Device to be a directory. For example, if you want your disk backups to go into the directory /home/bacula/backups, you could use the following:
Device {
Name = FileBackup
Media Type = File
Archive Device = /home/bacula/backups
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
}
Assuming you have the appropriate Storage resource in your Director's configuration file that references the above Device resource,
Storage {
Name = FileStorage
Address = ...
Password = ...
Device = FileBackup
Media Type = File
}
Bacula will then write the archive to the file /home/bacula/backups/<volume-name> where <volume-name> is the volume name of a Volume defined in the Pool. For example, if you have labeled a Volume named Vol001, Bacula will write to the file /home/bacula/backups/Vol001. Although you can later move the archive file to another directory, you should not rename it or it will become unreadable by Bacula. This is because each archive has the filename as part of the internal label, and the internal label must agree with the system filename before Bacula will use it.
Although this is quite simple, there are a number of problems, the first is that unless you specify otherwise, Bacula will always write to the same volume until you run out of disk space.
Some of the options you have, all of which are specified in the Pool record, are:
UseVolumeOnce = yes.
Maximum Volume Jobs = nnn.
Maximum Volume Bytes = mmmm.
Volume Use Duration = ttt.
Note that although you probably would not want to limit the number of bytes on a tape as you would on a disk Volume, the other options can be very useful in limiting the time Bacula will use a particular Volume (be it tape or disk). For example, the above directives can allow you to ensure that you rotate through a set of daily Volumes if you wish.
As mentioned above, each of those directives are specified in the Pool or Pools that you use for your Volumes. In the case of Maximum Volume Job, Maximum Volume Bytes, and Volume Use Duration, you can actually specify the desired value on a Volume by Volume basis. The value specified in the Pool record becomes the default when labeling new Volumes. As an example of the use of one of the above, suppose your Pool resource contains:
Pool {
Name = File
Pool Type = Backup
Volume Use Duration = 23h
}
then if you run a backup once a day (every 24 hours), Bacula will use a new Volume each backup because each Volume it writes can only be used for 23 hours after the first write.
Use of the above records brings up another problem - that of labeling your Volumes. For automated disk backup, you can either manually label each of your Volumes, or you can have Bacula automatically label new Volumes when they are needed. While, the automatic Volume labeling in version 1.30 and prior is a bit simplistic, but it does allow for automation, the features added in version 1.31 permit automatic creation of a wide variety of labels including information from environment variables and special Bacula Counter variables.
Please note that automatic Volume can also be used with tapes, but it is not nearly so practical since the tapes must be pre-mounted. This requires some user interaction. Automatic labeling from templates does NOT work with autochangers since Bacula will not access unknown slots. There are several methods of labeling all volumes in an autochanger magazine. For more information on this, please see the Autochanger chapter of this manual.
Automatic Volume labeling is enabled by making a change to both the Pool resource (Director) and to the Device resource (Storage daemon) shown above. In the case of the Pool resource, you must provide Bacula with a label format that it will use to create new names. In the simplest form, the label format is simply the Volume name, to which Bacula will append a four digit number. This number starts at 0001 and is incremented for each Volume the pool contains. Thus if you modify your Pool resource to be:
Pool {
Name = File
Pool Type = Backup
Volume Use Duration = 23h
LabelFormat = "Vol"
}
Bacula will create Volume names Vol0001, Vol0002, and so on when new Volumes are needed. Much more complex and elaborate labels can be created using variable expansion defined in the Variable Expansion chapter of this manual.
The second change that is necessary to make automatic labeling work is to give the Storage daemon permission to automatically label Volumes. Do so by adding LabelMedia = yes to the Device resource as follows:
Device {
Name = File
Media Type = File
Archive Device = /home/bacula/backups
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
LabelMedia = yes
}
You can find more details of the Label Format Pool record in Label Format description of the Pool resource records.
Automatic labeling discussed above brings up the problem of Volume management. With the above scheme, a new Volume will be created every day. If you have not specified Retention periods, your Catalog will continue to fill keeping track of all the files Bacula has backed up, and this procedure will create one new archive file (Volume) every day.
The tools Bacula gives you to help automatically manage these problems are the following:
The first three records (File Retention, Job Retention, and AutoPrune) determine the amount of time that Job and File records will remain in your Catalog, and they are discussed in detail in the Automatic Volume Recycling chapter of this manual.
Volume Retention, AutoPrune, and Recycle determine how long Bacula will keep your Volumes before reusing them, and they are also discussed in detail in the
Automatic Volume Recycling chapter of this manual.
The Maximum Volumes record can also be used in conjunction with the Volume Retention period to limit the total number of archive Volumes (files) that Bacula will create. By setting an appropriate Volume Retention period, a Volume will be purged just before it is needed and thus Bacula can cycle through a fixed set of Volumes. Cycling through a fixed set of Volumes can also be done by setting Recycle Oldest Volume = yes or Recycle Current Volume = yes. In this case, when Bacula needs a new Volume, it will prune the specified volume.
The following example is not very practical, but can be used to demonstrate the proof of concept in a relatively short period of time. The example consists of a single client that is backed up to a set of 12 archive files (Volumes). Each Volume is used (written) only once, and there are four Full saves done every hour (so the whole thing cycles around after three hours).
The Director's configuration file is as follows:
Director {
Name = my-dir
QueryFile = "~/bacula/bin/query.sql"
PidDirectory = "~/bacula/working"
WorkingDirectory = "~/bacula/working"
Password = dir_password
}
Schedule {
Name = "FourPerHour"
Run = Level=Full Pool=Recycle Storage=File hourly at 0:05
Run = Level=Full Pool=Recycle Storage=File hourly at 0:20
Run = Level=Full Pool=Recycle Storage=File hourly at 0:35
Run = Level=Full Pool=Recycle Storage=File hourly at 0:50
}
Job {
Name = "RecycleExample"
Type = Backup
Level = Full
Client = Rufus
FileSet= "Example FileSet"
Messages = Standard
Storage = FileStorage
Pool = Recycle
Schedule = FourPerHour
}
FileSet {
Name = "Example FileSet"
Include = compression=GZIP signature=SHA1 {
/home/kern/bacula/bin
}
}
Client {
Name = Rufus
Address = rufus
Catalog = BackupDB
Password = client_password
}
Storage {
Name = FileStorage
Address = rufus
Password = local_storage_password
Device = RecycleDir
Media Type = File
}
Catalog {
Name = BackupDB
dbname = bacula; user = bacula; password = ""
}
Messages {
Name = Standard
...
}
Pool {
Name = Recycle
Use Volume Once = yes
Pool Type = Backup
LabelFormat = "Vol"
AutoPrune = yes
VolumeRetention = 2h
Maximum Volumes = 12
Recycle = yes
}
and the Storage daemon's configuration file is:
Storage {
Name = my-sd
WorkingDirectory = "~/bacula/working"
Pid Directory = "~/bacula/working"
MaximumConcurrentJobs = 10
}
Director {
Name = my-dir
Password = local_storage_password
}
Device {
Name = RecycleDir
Media Type = File
Archive Device = /home/bacula/backups
LabelMedia = yes;
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
}
Messages {
Name = Standard
director = my-dir = all
}
In this example, the Jobs will be backed up to directory /home/bacula/backups with Volume names Vol0001, Vol0002, ... Vol0012. Every backup Job will write a new volume cycling through the volume numbers, and two hours after a job has started, the volume will be pruned Volume Retention = 2h.
With a little bit of work, you can change the above example into a weekly or monthly cycle (take care about the amount of archive disk space used).
Bacula can, of course, use multiple disks, but in general, each disk must be a separate Device specification in the Storage daemon's conf file, and you must then select what clients to backup to each disk.
The situation is a bit more complicated if you want to treat two disk drives logically as a single drive, which Bacula does not directly support. However, it is possible to back up your data to multiple disks as if they were a single drive by linking the Volumes from the first disk to the second disk.
For example, assume that you have two disks named /disk1 and /disk2>. If you then create a standard Storage daemon Device resource for backing up to the first disk, it will look like the following:
Device {
Name = client1
Media Type = File
Archive Device = /disk1
LabelMedia = yes;
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
}
Since there is no way to get the above Device resource to reference both /disk1 and /disk2 we do it by pre-creating Volumes on /disk2 with the following:
ln -s /disk2/Disk2-vol001 /disk1/Disk2-vol001 ln -s /disk2/Disk2-vol002 /disk1/Disk2-vol002 ln -s /disk2/Disk2-vol003 /disk1/Disk2-vol003 ...
At this point, you can label the Volumes as Volume Disk2-vol001, Disk2-vol002, ... and Bacula will use them as if they were on /disk1 but actually write the data to /disk2. The only minor inconvenience with this method is that you must explicitly name the disks and cannot use automatic labeling unless you arrange to have the labels exactly match the links you have created.
If we take the above example and add a second Client, here are a few considerations:
In this example, we have two clients, each with a different Pool and a different number of archive files retained. They also write to different directories with different Volume labeling.
The Director's configuration file is as follows:
Director {
Name = my-dir
QueryFile = "~/bacula/bin/query.sql"
PidDirectory = "~/bacula/working"
WorkingDirectory = "~/bacula/working"
Password = dir_password
}
# Basic weekly schedule
Schedule {
Name = "WeeklySchedule"
Run = Level=Full fri at 1:30
Run = Level=Incremental sat-thu at 1:30
}
FileSet {
Name = "Example FileSet"
Include = compression=GZIP signature=SHA1 {
/home/kern/bacula/bin
}
}
Job {
Name = "Backup-client1"
Type = Backup
Level = Full
Client = client1
FileSet= "Example FileSet"
Messages = Standard
Storage = File1
Pool = client1
Schedule = "WeeklySchedule"
}
Job {
Name = "Backup-client2"
Type = Backup
Level = Full
Client = client2
FileSet= "Example FileSet"
Messages = Standard
Storage = File2
Pool = client2
Schedule = "WeeklySchedule"
}
Client {
Name = client1
Address = client1
Catalog = BackupDB
Password = client1_password
File Retention = 7d
}
Client {
Name = client2
Address = client2
Catalog = BackupDB
Password = client2_password
}
# Two Storage definitions permits different directories
Storage {
Name = File1
Address = rufus
Password = local_storage_password
Device = client1
Media Type = File
}
Storage {
Name = File2
Address = rufus
Password = local_storage_password
Device = client2
Media Type = File
}
Catalog {
Name = BackupDB
dbname = bacula; user = bacula; password = ""
}
Messages {
Name = Standard
...
}
# Two pools permits different cycling periods and Volume names
# Cycle through 15 Volumes (two weeks)
Pool {
Name = client1
Use Volume Once = yes
Pool Type = Backup
LabelFormat = "Client1-"
AutoPrune = yes
VolumeRetention = 13d
Maximum Volumes = 15
Recycle = yes
}
# Cycle through 8 Volumes (1 week)
Pool {
Name = client2
Use Volume Once = yes
Pool Type = Backup
LabelFormat = "Client2-"
AutoPrune = yes
VolumeRetention = 6d
Maximum Volumes = 8
Recycle = yes
}
and the Storage daemon's configuration file is:
Storage {
Name = my-sd
WorkingDirectory = "~/bacula/working"
Pid Directory = "~/bacula/working"
MaximumConcurrentJobs = 10
}
Director {
Name = my-dir
Password = local_storage_password
}
# Archive directory for Client1
Device {
Name = client1
Media Type = File
Archive Device = /home/bacula/client1
LabelMedia = yes;
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
}
# Archive directory for Client2
Device {
Name = client2
Media Type = File
Archive Device = /home/bacula/client2
LabelMedia = yes;
Random Access = Yes;
AutomaticMount = yes;
RemovableMedia = no;
AlwaysOpen = no;
}
Messages {
Name = Standard
director = my-dir = all
}