4 \chapter{Backup Strategies}
5 \label{StrategiesChapter}
6 \index[general]{Strategies!Backup }
7 \index[general]{Backup Strategies }
9 Although Recycling and Backing Up to Disk Volume have been discussed in
10 previous chapters, this chapter is meant to give you an overall view of
11 possible backup strategies and to explain their advantages and disadvantages.
14 \section{Simple One Tape Backup}
15 \index[general]{Backup!Simple One Tape }
16 \index[general]{Simple One Tape Backup }
18 Probably the simplest strategy is to back everything up to a single tape and
19 insert a new (or recycled) tape when it fills and Bacula requests a new one.
21 \subsection{Advantages}
22 \index[general]{Advantages }
25 \item The operator intervenes only when a tape change is needed. (once a
27 \item There is little chance of operator error because the tape is not
29 \item A minimum number of tapes will be needed for a full restore. Typically
30 the best case will be one tape and worst two.
31 \item You can easily arrange for the Full backup to occur a different night
32 of the month for each system, thus load balancing and shortening the backup
36 \subsection{Disadvantages}
37 \index[general]{Disadvantages }
40 \item If your site burns down, you will lose your current backups, and in my
41 case about a month of data.
42 \item After a tape fills and you have put in a blank tape, the backup will
43 continue, and this will generally happen during working hours.
46 \subsection{Practical Details}
47 \index[general]{Details!Practical }
48 \index[general]{Practical Details }
50 This system is very simple. When the tape fills and Bacula requests a new
51 tape, you {\bf unmount} the tape from the Console program, insert a new tape
52 and {\bf label} it. In most cases after the label, Bacula will automatically
53 mount the tape and resume the backup. Otherwise, you simply {\bf mount} the
56 Using this strategy, one typically does a Full backup once a week followed by
57 daily Incremental backups. To minimize the amount of data written to the tape,
58 one can do a Full backup once a month on the first Sunday of the
59 month, a Differential backup on the 2nd-5th Sunday of the month, and
60 incremental backups the rest of the week.
63 \section{Manually Changing Tapes}
64 \index[general]{Tapes!Manually Changing }
65 \index[general]{Manually Changing Tapes }
67 If you use the strategy presented above, Bacula will ask you to change the
68 tape, and you will {\bf unmount} it and then remount it when you have inserted
71 If you do not wish to interact with Bacula to change each tape, there are
72 several ways to get Bacula to release the tape:
75 \item In your Storage daemon's Device resource, set
77 In this case, Bacula will release the tape after every job. If you run
78 several jobs, the tape will be rewound and repositioned to the end at the
79 beginning of every job. This is not very efficient, but does let you change
80 the tape whenever you want.
81 \item Use a {\bf RunAfterJob} statement to run a script after your last job.
82 This could also be an {\bf Admin} job that runs after all your backup jobs.
83 The script could be something like:
88 /full-path/bconsole -c /full-path/bconsole.conf <<END_OF_DATA
89 release storage=your-storage-name
95 In this example, you would have {\bf AlwaysOpen=yes}, but the {\bf release}
96 command would tell Bacula to rewind the tape and on the next job assume the
97 tape has changed. This strategy may not work on some systems, or on
98 autochangers because Bacula will still keep the drive open.
99 \item The final strategy is similar to the previous case except that you
100 would use the unmount command to force Bacula to release the drive. Then you
101 would eject the tape, and remount it as follows:
106 /full-path/bconsole -c /full-path/bconsole.conf <\<END_OF_DATA
107 unmount storage=your-storage-name
109 # the following is a shell command
111 /full-path/bconsole -c /full-path/bconsole.conf <<END_OF_DATA
112 mount storage=your-storage-name
122 \section{Daily Tape Rotation}
123 \index[general]{Rotation!Daily Tape }
124 \index[general]{Daily Tape Rotation }
126 This scheme is quite different from the one mentioned above in that a Full
127 backup is done to a different tape every day of the week. Generally, the
128 backup will cycle continuously through five or six tapes each week. Variations are
129 to use a different tape each Friday, and possibly at the beginning of the
130 month. Thus if backups are done Monday through Friday only, you need only five
131 tapes, and by having two Friday tapes, you need a total of six tapes. Many sites
132 run this way, or using modifications of it based on two week cycles or longer.
135 \subsection{Advantages}
136 \index[general]{Advantages }
139 \item All the data is stored on a single tape, so recoveries are simple and
141 \item Assuming the previous day's tape is taken offsite each day, a maximum
142 of one days data will be lost if the site burns down.
145 \subsection{Disadvantages}
146 \index[general]{Disadvantages }
149 \item The tape must be changed every day requiring a lot of operator
151 \item More errors will occur because of human mistakes.
152 \item If the wrong tape is inadvertently mounted, the Backup for that day
153 will not occur exposing the system to data loss.
154 \item There is much more movement of the tape each day (rewinds) leading to
155 shorter tape drive life time.
156 \item Initial setup of Bacula to run in this mode is more complicated than
157 the Single tape system described above.
158 \item Depending on the number of systems you have and their data capacity, it
159 may not be possible to do a Full backup every night for time reasons or
160 reasons of tape capacity.
163 \subsection{Practical Details}
164 \index[general]{Details!Practical }
165 \index[general]{Practical Details }
167 The simplest way to "force" Bacula to use a different tape each day is to
168 define a different Pool for each day of the the week a backup is done. In
169 addition, you will need to specify appropriate Job and File retention periods
170 so that Bacula will relabel and overwrite the tape each week rather than
171 appending to it. Nic Bellamy has supplied an actual working model of this
172 which we include here.
174 What is important is to create a different Pool for each day of the week, and
175 on the {\bf run} statement in the Schedule, to specify which Pool is to be
176 used. He has one Schedule that accomplishes this, and a second Schedule that
177 does the same thing for the Catalog backup run each day after the main backup
178 (Priorities were not available when this script was written). In addition, he
179 uses a {\bf Max Start Delay} of 22 hours so that if the wrong tape is
180 premounted by the operator, the job will be automatically canceled, and the
181 backup cycle will re-synchronize the next day. He has named his Friday Pool
182 {\bf WeeklyPool} because in that Pool, he wishes to have several tapes to be
183 able to restore to a time older than one week.
185 And finally, in his Storage daemon's Device resource, he has {\bf Automatic
186 Mount = yes} and {\bf Always Open = No}. This is necessary for the tape
187 ejection to work in his {\bf end\_of\_backup.sh} script below.
189 For example, his bacula-dir.conf file looks like the following:
194 # /etc/bacula/bacula-dir.conf
196 # Bacula Director Configuration file
201 QueryFile = "/etc/bacula/query.sql"
202 WorkingDirectory = "/var/lib/bacula"
203 PidDirectory = "/var/run"
204 SubSysDirectory = "/var/lock/subsys"
205 Maximum Concurrent Jobs = 1
206 Password = "console-pass"
210 # Define the main nightly save backup job
217 Schedule = "WeeklyCycle"
221 Write Bootstrap = "/var/lib/bacula/NightlySave.bsr"
222 Max Start Delay = 22h
224 # Backup the catalog database (after the nightly save)
226 Name = "BackupCatalog"
230 Schedule = "WeeklyCycleAfterBackup"
234 # This creates an ASCII copy of the catalog
235 RunBeforeJob = "/usr/lib/bacula/make_catalog_backup -u bacula"
236 # This deletes the copy of the catalog, and ejects the tape
237 RunAfterJob = "/etc/bacula/end_of_backup.sh"
238 Write Bootstrap = "/var/lib/bacula/BackupCatalog.bsr"
239 Max Start Delay = 22h
241 # Standard Restore template, changed by Console program
243 Name = "RestoreFiles"
250 Where = /tmp/bacula-restores
252 # List of files to be backed up
255 Include = signature=MD5 {
259 Exclude = { /proc /tmp /.journal }
262 # When to do the backups
266 Run = Level=Full Pool=MondayPool Monday at 8:00pm
267 Run = Level=Full Pool=TuesdayPool Tuesday at 8:00pm
268 Run = Level=Full Pool=WednesdayPool Wednesday at 8:00pm
269 Run = Level=Full Pool=ThursdayPool Thursday at 8:00pm
270 Run = Level=Full Pool=WeeklyPool Friday at 8:00pm
272 # This does the catalog. It starts after the WeeklyCycle
274 Name = "WeeklyCycleAfterBackup"
275 Run = Level=Full Pool=MondayPool Monday at 8:15pm
276 Run = Level=Full Pool=TuesdayPool Tuesday at 8:15pm
277 Run = Level=Full Pool=WednesdayPool Wednesday at 8:15pm
278 Run = Level=Full Pool=ThursdayPool Thursday at 8:15pm
279 Run = Level=Full Pool=WeeklyPool Friday at 8:15pm
281 # This is the backup of the catalog
284 Include = signature=MD5 {
285 /var/lib/bacula/bacula.sql
288 # Client (File Services) to backup
294 Password = "client-pass"
299 # Definition of file storage device
304 Password = "storage-pass"
308 # Generic catalog service
311 dbname = bacula; user = bacula; password = ""
313 # Reasonable message delivery -- send almost all to email address
317 mailcommand = "/usr/sbin/bsmtp -h localhost -f \"\(Bacula\) %r\"
318 -s \"Bacula: %t %e of %c %l\" %r"
319 operatorcommand = "/usr/sbin/bsmtp -h localhost -f \"\(Bacula\) %r\"
320 -s \"Bacula: Intervention needed for %j\" %r"
321 mail = root@localhost = all, !skipped
322 operator = root@localhost = mount
323 console = all, !skipped, !saved
324 append = "/var/lib/bacula/log" = all, !skipped
329 # Default Pool for jobs, but will hold no actual volumes
339 Volume Retention = 6d
340 Maximum Volume Jobs = 2
347 Volume Retention = 6d
348 Maximum Volume Jobs = 2
355 Volume Retention = 6d
356 Maximum Volume Jobs = 2
363 Volume Retention = 6d
364 Maximum Volume Jobs = 2
371 Volume Retention = 12d
372 Maximum Volume Jobs = 2
378 Note, the mailcommand and operatorcommand should be on a single line each.
379 They were split to preserve the proper page width. In order to get Bacula to
380 release the tape after the nightly backup, he uses a {\bf RunAfterJob} script
381 that deletes the ASCII copy of the database back and then rewinds and ejects
382 the tape. The following is a copy of {\bf end\_of\_backup.sh}
387 /usr/lib/bacula/delete_catalog_backup
394 Finally, if you list his Volumes, you get something like the following:
399 Using default Catalog name=MyCatalog DB=bacula
401 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
402 | MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
403 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
404 | 5 | Friday_1 | MLR1 | Used | 2157171998| 2003-07-11 20:20| 103680| 1 |
405 | 6 | Friday_2 | MLR1 | Append | 0 | 0 | 103680| 1 |
406 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
408 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
409 | MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
410 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
411 | 2 | Monday | MLR1 | Used | 2260942092| 2003-07-14 20:20| 518400| 1 |
412 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
414 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
415 | MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
416 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
417 | 3 | Tuesday | MLR1 | Used | 2268180300| 2003-07-15 20:20| 518400| 1 |
418 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
420 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
421 | MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
422 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
423 | 4 | Wednesday | MLR1 | Used | 2138871127| 2003-07-09 20:2 | 518400| 1 |
424 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
426 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
427 | MeId| VolumeName| MedTyp| VolStat| VolBytes | LastWritten | VolRet| Recyc|
428 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
429 | 1 | Thursday | MLR1 | Used | 2146276461| 2003-07-10 20:50| 518400| 1 |
430 +-----+-----------+-------+--------+-----------+-----------------+-------+------+
436 Note, I have truncated a number of the columns so that the information fits on