--- /dev/null
+%%
+%%
+
+\chapter{Backup Strategies}
+\label{StrategiesChapter}
+\index[general]{Strategies!Backup }
+\index[general]{Backup Strategies }
+
+Although Recycling and Backing Up to Disk Volume have been discussed in
+previous chapters, this chapter is meant to give you an overall view of
+possible backup strategies and to explain their advantages and disadvantages.
+\label{Simple}
+
+\section{Simple One Tape Backup}
+\index[general]{Backup!Simple One Tape }
+\index[general]{Simple One Tape Backup }
+
+Probably the simplest strategy is to back everything up to a single tape and
+insert a new (or recycled) tape when it fills and Bacula requests a new one.
+
+\subsection{Advantages}
+\index[general]{Advantages }
+
+\begin{itemize}
+\item The operator intervenes only when a tape change is needed. (once a
+ month at my site).
+\item There is little chance of operator error because the tape is not
+ changed daily.
+\item A minimum number of tapes will be needed for a full restore. Typically
+ the best case will be one tape and worst two.
+\item You can easily arrange for the Full backup to occur a different night
+ of the month for each system, thus load balancing and shortening the backup
+ time.
+\end{itemize}
+
+\subsection{Disadvantages}
+\index[general]{Disadvantages }
+
+\begin{itemize}
+\item If your site burns down, you will lose your current backups, and in my
+ case about a month of data.
+\item After a tape fills and you have put in a blank tape, the backup will
+ continue, and this will generally happen during working hours.
+ \end{itemize}
+
+\subsection{Practical Details}
+\index[general]{Details!Practical }
+\index[general]{Practical Details }
+
+This system is very simple. When the tape fills and Bacula requests a new
+tape, you {\bf unmount} the tape from the Console program, insert a new tape
+and {\bf label} it. In most cases after the label, Bacula will automatically
+mount the tape and resume the backup. Otherwise, you simply {\bf mount} the
+tape.
+
+Using this strategy, one typically does a Full backup once a week followed by
+daily Incremental backups. To minimize the amount of data written to the tape,
+one can do a Full backup once a month on the first Sunday of the
+month, a Differential backup on the 2nd-5th Sunday of the month, and
+incremental backups the rest of the week.
+\label{Manual}
+
+\section{Manually Changing Tapes}
+\index[general]{Tapes!Manually Changing }
+\index[general]{Manually Changing Tapes }
+
+If you use the strategy presented above, Bacula will ask you to change the
+tape, and you will {\bf unmount} it and then remount it when you have inserted
+the new tape.
+
+If you do not wish to interact with Bacula to change each tape, there are
+several ways to get Bacula to release the tape:
+
+\begin{itemize}
+\item In your Storage daemon's Device resource, set
+ {\bf AlwaysOpen = no}
+ In this case, Bacula will release the tape after every job. If you run
+ several jobs, the tape will be rewound and repositioned to the end at the
+ beginning of every job. This is not very efficient, but does let you change
+ the tape whenever you want.
+\item Use a {\bf RunAfterJob} statement to run a script after your last job.
+ This could also be an {\bf Admin} job that runs after all your backup jobs.
+ The script could be something like:
+
+\footnotesize
+\begin{verbatim}
+ #!/bin/sh
+ /full-path/bconsole -c /full-path/bconsole.conf <<END_OF_DATA
+ release storage=your-storage-name
+ END_OF_DATA
+
+\end{verbatim}
+\normalsize
+
+In this example, you would have {\bf AlwaysOpen=yes}, but the {\bf release}
+command would tell Bacula to rewind the tape and on the next job assume the
+tape has changed. This strategy may not work on some systems, or on
+autochangers because Bacula will still keep the drive open.
+\item The final strategy is similar to the previous case except that you
+ would use the unmount command to force Bacula to release the drive. Then you
+ would eject the tape, and remount it as follows:
+
+\footnotesize
+\begin{verbatim}
+ #!/bin/sh
+ /full-path/bconsole -c /full-path/bconsole.conf <\<END_OF_DATA
+ unmount storage=your-storage-name
+ END_OF_DATA
+ # the following is a shell command
+ mt eject
+ /full-path/bconsole -c /full-path/bconsole.conf <<END_OF_DATA
+ mount storage=your-storage-name
+ END_OF_DATA
+
+\end{verbatim}
+\normalsize
+
+\end{itemize}
+
+\label{Daily}
+
+\section{Daily Tape Rotation}
+\index[general]{Rotation!Daily Tape }
+\index[general]{Daily Tape Rotation }
+
+This scheme is quite different from the one mentioned above in that a Full
+backup is done to a different tape every day of the week. Generally, the
+backup will cycle continuously through five or six tapes each week. Variations are
+to use a different tape each Friday, and possibly at the beginning of the
+month. Thus if backups are done Monday through Friday only, you need only five
+tapes, and by having two Friday tapes, you need a total of six tapes. Many sites
+run this way, or using modifications of it based on two week cycles or longer.
+
+
+\subsection{Advantages}
+\index[general]{Advantages }
+
+\begin{itemize}
+\item All the data is stored on a single tape, so recoveries are simple and
+ faster.
+\item Assuming the previous day's tape is taken offsite each day, a maximum
+ of one days data will be lost if the site burns down.
+ \end{itemize}
+
+\subsection{Disadvantages}
+\index[general]{Disadvantages }
+
+\begin{itemize}
+\item The tape must be changed every day requiring a lot of operator
+ intervention.
+\item More errors will occur because of human mistakes.
+\item If the wrong tape is inadvertently mounted, the Backup for that day
+ will not occur exposing the system to data loss.
+\item There is much more movement of the tape each day (rewinds) leading to
+ shorter tape drive life time.
+\item Initial setup of Bacula to run in this mode is more complicated than
+ the Single tape system described above.
+\item Depending on the number of systems you have and their data capacity, it
+ may not be possible to do a Full backup every night for time reasons or
+ reasons of tape capacity.
+\end{itemize}
+
+\subsection{Practical Details}
+\index[general]{Details!Practical }
+\index[general]{Practical Details }
+
+The simplest way to "force" Bacula to use a different tape each day is to
+define a different Pool for each day of the the week a backup is done. In
+addition, you will need to specify appropriate Job and File retention periods
+so that Bacula will relabel and overwrite the tape each week rather than
+appending to it. Nic Bellamy has supplied an actual working model of this
+which we include here.
+
+What is important is to create a different Pool for each day of the week, and
+on the {\bf run} statement in the Schedule, to specify which Pool is to be
+used. He has one Schedule that accomplishes this, and a second Schedule that
+does the same thing for the Catalog backup run each day after the main backup
+(Priorities were not available when this script was written). In addition, he
+uses a {\bf Max Start Delay} of 22 hours so that if the wrong tape is
+premounted by the operator, the job will be automatically canceled, and the
+backup cycle will re-synchronize the next day. He has named his Friday Pool
+{\bf WeeklyPool} because in that Pool, he wishes to have several tapes to be
+able to restore to a time older than one week.
+
+And finally, in his Storage daemon's Device resource, he has {\bf Automatic
+Mount = yes} and {\bf Always Open = No}. This is necessary for the tape
+ejection to work in his {\bf end\_of\_backup.sh} script below.
+
+For example, his bacula-dir.conf file looks like the following:
+
+\footnotesize
+\begin{verbatim}
+
+# /etc/bacula/bacula-dir.conf
+#
+# Bacula Director Configuration file
+#
+Director {
+ Name = ServerName
+ DIRport = 9101
+ QueryFile = "/etc/bacula/query.sql"
+ WorkingDirectory = "/var/lib/bacula"
+ PidDirectory = "/var/run"
+ SubSysDirectory = "/var/lock/subsys"
+ Maximum Concurrent Jobs = 1
+ Password = "console-pass"
+ Messages = Standard
+}
+#
+# Define the main nightly save backup job
+#
+Job {
+ Name = "NightlySave"
+ Type = Backup
+ Client = ServerName
+ FileSet = "Full Set"
+ Schedule = "WeeklyCycle"
+ Storage = Tape
+ Messages = Standard
+ Pool = Default
+ Write Bootstrap = "/var/lib/bacula/NightlySave.bsr"
+ Max Start Delay = 22h
+}
+# Backup the catalog database (after the nightly save)
+Job {
+ Name = "BackupCatalog"
+ Type = Backup
+ Client = ServerName
+ FileSet = "Catalog"
+ Schedule = "WeeklyCycleAfterBackup"
+ Storage = Tape
+ Messages = Standard
+ Pool = Default
+ # This creates an ASCII copy of the catalog
+ # WARNING!!! Passing the password via the command line is insecure.
+ # see comments in make_catalog_backup for details.
+ RunBeforeJob = "/usr/lib/bacula/make_catalog_backup -u bacula"
+ # This deletes the copy of the catalog, and ejects the tape
+ RunAfterJob = "/etc/bacula/end_of_backup.sh"
+ Write Bootstrap = "/var/lib/bacula/BackupCatalog.bsr"
+ Max Start Delay = 22h
+}
+# Standard Restore template, changed by Console program
+Job {
+ Name = "RestoreFiles"
+ Type = Restore
+ Client = ServerName
+ FileSet = "Full Set"
+ Storage = Tape
+ Messages = Standard
+ Pool = Default
+ Where = /tmp/bacula-restores
+}
+# List of files to be backed up
+FileSet {
+ Name = "Full Set"
+ Include = signature=MD5 {
+ /
+ /data
+ }
+ Exclude = { /proc /tmp /.journal }
+}
+#
+# When to do the backups
+#
+Schedule {
+ Name = "WeeklyCycle"
+ Run = Level=Full Pool=MondayPool Monday at 8:00pm
+ Run = Level=Full Pool=TuesdayPool Tuesday at 8:00pm
+ Run = Level=Full Pool=WednesdayPool Wednesday at 8:00pm
+ Run = Level=Full Pool=ThursdayPool Thursday at 8:00pm
+ Run = Level=Full Pool=WeeklyPool Friday at 8:00pm
+}
+# This does the catalog. It starts after the WeeklyCycle
+Schedule {
+ Name = "WeeklyCycleAfterBackup"
+ Run = Level=Full Pool=MondayPool Monday at 8:15pm
+ Run = Level=Full Pool=TuesdayPool Tuesday at 8:15pm
+ Run = Level=Full Pool=WednesdayPool Wednesday at 8:15pm
+ Run = Level=Full Pool=ThursdayPool Thursday at 8:15pm
+ Run = Level=Full Pool=WeeklyPool Friday at 8:15pm
+}
+# This is the backup of the catalog
+FileSet {
+ Name = "Catalog"
+ Include = signature=MD5 {
+ /var/lib/bacula/bacula.sql
+ }
+}
+# Client (File Services) to backup
+Client {
+ Name = ServerName
+ Address = dionysus
+ FDPort = 9102
+ Catalog = MyCatalog
+ Password = "client-pass"
+ File Retention = 30d
+ Job Retention = 30d
+ AutoPrune = yes
+}
+# Definition of file storage device
+Storage {
+ Name = Tape
+ Address = dionysus
+ SDPort = 9103
+ Password = "storage-pass"
+ Device = Tandberg
+ Media Type = MLR1
+}
+# Generic catalog service
+Catalog {
+ Name = MyCatalog
+ dbname = bacula; user = bacula; password = ""
+}
+# Reasonable message delivery -- send almost all to email address
+# and to the console
+Messages {
+ Name = Standard
+ mailcommand = "/usr/sbin/bsmtp -h localhost -f \"\(Bacula\) %r\"
+ -s \"Bacula: %t %e of %c %l\" %r"
+ operatorcommand = "/usr/sbin/bsmtp -h localhost -f \"\(Bacula\) %r\"
+ -s \"Bacula: Intervention needed for %j\" %r"
+ mail = root@localhost = all, !skipped
+ operator = root@localhost = mount
+ console = all, !skipped, !saved
+ append = "/var/lib/bacula/log" = all, !skipped
+}
+
+# Pool definitions
+#
+# Default Pool for jobs, but will hold no actual volumes
+Pool {
+ Name = Default
+ Pool Type = Backup
+}
+Pool {
+ Name = MondayPool
+ Pool Type = Backup
+ Recycle = yes
+ AutoPrune = yes
+ Volume Retention = 6d
+ Maximum Volume Jobs = 2
+}
+Pool {
+ Name = TuesdayPool
+ Pool Type = Backup
+ Recycle = yes
+ AutoPrune = yes
+ Volume Retention = 6d
+ Maximum Volume Jobs = 2
+}
+Pool {
+ Name = WednesdayPool
+ Pool Type = Backup
+ Recycle = yes
+ AutoPrune = yes
+ Volume Retention = 6d
+ Maximum Volume Jobs = 2
+}
+Pool {
+ Name = ThursdayPool
+ Pool Type = Backup
+ Recycle = yes
+ AutoPrune = yes
+ Volume Retention = 6d
+ Maximum Volume Jobs = 2
+}
+Pool {
+ Name = WeeklyPool
+ Pool Type = Backup
+ Recycle = yes
+ AutoPrune = yes
+ Volume Retention = 12d
+ Maximum Volume Jobs = 2
+}
+# EOF
+\end{verbatim}
+\normalsize
+
+Note, the mailcommand and operatorcommand should be on a single line each.
+They were split to preserve the proper page width. In order to get Bacula to
+release the tape after the nightly backup, he uses a {\bf RunAfterJob} script
+that deletes the ASCII copy of the database back and then rewinds and ejects
+the tape. The following is a copy of {\bf end\_of\_backup.sh}
+
+\footnotesize
+\begin{verbatim}
+#! /bin/sh
+/usr/lib/bacula/delete_catalog_backup
+mt rewind
+mt eject
+exit 0
+\end{verbatim}
+\normalsize
+
+Finally, if you list his Volumes, you get something like the following:
+
+\footnotesize
+\begin{verbatim}
+*list media
+Using default Catalog name=MyCatalog DB=bacula
+Pool: WeeklyPool
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| 5 | Friday_1 | MLR1 | Used | 2157171998| 2003-07-11 20:20| 103680| 1 |
+| 6 | Friday_2 | MLR1 | Append | 0 | 0 | 103680| 1 |
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+Pool: MondayPool
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| 2 | Monday | MLR1 | Used | 2260942092| 2003-07-14 20:20| 518400| 1 |
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+Pool: TuesdayPool
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| 3 | Tuesday | MLR1 | Used | 2268180300| 2003-07-15 20:20| 518400| 1 |
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+Pool: WednesdayPool
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| 4 | Wednesday | MLR1 | Used | 2138871127| 2003-07-09 20:2 | 518400| 1 |
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+Pool: ThursdayPool
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+| 1 | Thursday | MLR1 | Used | 2146276461| 2003-07-10 20:50| 518400| 1 |
++-----+-----------+-------+--------+-----------+-----------------+-------+------+
+Pool: Default
+No results to list.
+\end{verbatim}
+\normalsize
+
+Note, I have truncated a number of the columns so that the information fits on
+the width of a page.
projects / bacula / docs / blobdiff