1AMPGSQL(8)              System Administration Commands              AMPGSQL(8)
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NAME

6       ampgsql - Amanda Application to interface with PostgreSQL
7

DESCRIPTION

9       Ampgsql is an Amanda Application API script. It should not be run by
10       users directly. It implements on-line backups of PostgreSQL databases
11       in conjunction with WAL archiving.
12
13           Note
14           Tablespaces are not currently supported.
15
16           Note
17           On versions of PostgreSQL earlier than 8.2, if the database is
18           quiet during a full backup, then the backup may not complete until
19           enough database activity takes place to trigger the archiving of
20           the current WAL file. Consider adjusting the PG-MAX-WAL-WAIT
21           property from its default (60s) to compensate. Note that you will
22           need to increase dtimeout on the server accordingly.
23

DISKLIST

25       The diskdevice must be the cluster data directory, if it is
26       "/var/lib/pgsql/data":
27         HOST DISKNAME /var/lib/pgsql/data DUMPTYPE
28       or
29         HOST /var/lib/pgsql/data DUMTYPE
30

OPERATION

32       This application implements the backup strategy described in
33       http://www.postgresql.org/docs/current/static/continuous-archiving.html.
34       For a level zero (full) backup, ampgsql:
35
36       •   execute PG_START_BACKUP()
37
38       •   dump the data directory
39
40       •   execute PG_STOP_BACKUP()
41
42       •   wait for the final WAL file to be archived
43
44       •   back up the required WAL files
45
46       •   optionally delete WAL files that are no longer necessary
47
48       The two dumps are made with GNU Tar, to data_dir.tar and archive_dir,
49       respectively. They are then combined into a single tar file.
50
51       A level N backup creates a single tar file containing all WAL files
52       since the previous level N-1 backup.
53

PROPERTIES

55       This section lists the amanda.conf(5) properties that control ampsql's
56       functionality. See amanda-applications(7) for information on
57       application properties and how they are configured.
58
59       ARCHIVEDIR
60           Directory that WAL segment files are archived to, as specified by
61           the archive_command in PosgreSQL's postgresql.conf. The amanda user
62           on the client must have at least read and execute permission on
63           this directory, and preferably write. Without write permission,
64           Amanda cannot clean up expired WAL and backup files.
65
66       CLEANUPWAL
67           Whether or not to remove old WAL segment files during base backups.
68           Defaults to yes.
69
70       DB
71           Database to connect to. Defaults to "template1" (which exists by
72           default).
73
74       DIRECTORY
75           For restore command only, the data is recoved in that directory.
76           Must be a unix path.
77
78       FULL-WAL
79           Which WAL files to archive when doing a full backup.
80
81           FULL
82               Backup all WAL files since the previous full backup.
83
84           INCR
85               Backup all WAL files since the previous backup (incr or full).
86
87           NO
88               Backup all WAL files required for that full backup
89
90           The default is "INCR".
91
92       GNUTAR-PATH
93           Path to the GNU tar executable. This option only has an effect
94           during restore. The default is set when Amanda is built by the
95           --with-gnutar configure option.
96
97       HOST
98           Host to connect to. If it starts with "/" it will be interepreted
99           as a directory that holds the socket file. PostgreSQL defaults to
100           /tmp.
101
102       INCREMENTAL
103           Default: NO. If set to "YES", then backup only the WAL files since
104           the previous backup.
105
106           It reduce the size of the backup, but amanda will not be able to
107           restore all incrementals, the restore must be done manually.It is
108           easier to set the dumptype bump* parameter to force a bump at every
109           backup.
110
111       MAX-WAL-WAIT
112           The maximum amount of time to wait for PG_STOP_BACKUP to archive a
113           WAL file. In versions of PostgreSQL before 8.2, PG_STOP_BACKUP does
114           not automatically archive the latest WAL file, so a quiet database
115           may wait a very long time before archiving the WAL file. Default:
116           60 seconds. Set to 0 to wait forever.
117
118       PASSFILE
119           Connect using the creditials in this file. Each line should have
120           the format "hostname:port:database:username:password". The
121           permissions must permit it to be read only by the user, or the file
122           will not be used. Only usable with Postgres 8.1 and up.
123
124       PORT
125           The TCP port to connect to, or the suffix of the socket file.
126           PostgreSQL defaults to 5432.
127
128       PSQL-PATH
129           Path to the psql binary. If not specified, the PATH environment
130           variable will be searched.
131
132       REMOVE-FULL-WAL
133           Default: YES. Remove all WAL files included in the full backup.
134
135       REMOVE-INCREMENTAL-WAL
136           Default: NO. If set to "YES" then remove all WAL files included in
137           the incremental backup.
138
139       STATEDIR
140           Directory for saving state about backups already made. The default
141           is set when Amanda is built by the --with-gnutar-listdir configure
142           option.
143
144       TMPDIR
145           Directory to use for temporary files during the backup process. It
146           should have enough space to store a complete copy of the database.
147           The default is set when Amanda is built by the --with-tmpdir
148           configure option.
149
150       USER
151           User to connect as. It must be a superuser.
152
153       VERBOSE
154           Do not use the --quiet output of psql.
155

CLIENT PROPERTIES

157       Client properties are deprecated. All properties should be set in the
158       dumptype.
159
160       This section lists the amanda-client.conf(5) properties that control
161       ampsql's functionality. If a property is prefixed with the diskname and
162       an underscore, then it will be used when that diskname is being backed
163       up. For example, if the properties PG-DATADIR and foo-PG-DATADIR are
164       set, the value of PG-DATADIR will be used when bar and baz are being
165       backed up, but foo-PG-DATADIR will be used when foo is being backed up.
166       Disknames are specified in the disklist(5).
167
168       PG-ARCHIVEDIR
169
170           Directory that WAL segment files are archived to, as specified by
171           the archive_command in PosgreSQL's postgresql.conf.  The amanda
172           user on the client must have at least read and execute permission
173           on this directory, and preferably write.  Without write permission,
174           Amanda cannot clean up expired WAL and backup files.
175
176       PG-CLEANUPWAL
177
178           Whether or not to remove old WAL segment files during base backups.
179           Defaults to yes.
180
181       PG-DATADIR
182
183           Cluster data directory
184
185       PG-DB
186
187           Database to connect to. Defaults to "template1" (which exists by
188           default).
189
190       PG-HOST
191
192           Host to connect to. If it starts with "/" it will be interepreted
193           as a directory that holds the socket file. PostgreSQL defaults to
194           /tmp.
195
196       PG-MAX-WAL-WAIT
197           The maximum amount of time to wait for PG_STOP_BACKUP to archive a
198           WAL file. In versions of PostgreSQL before 8.2, PG_STOP_BACKUP does
199           not automatically archive the latest WAL file, so a quiet database
200           may wait a very long time before archiving the WAL file. Default:
201           60 seconds. Set to 0 to wait forever.
202
203       PG-PASSFILE
204
205           Connect using the creditials in this file. Each line should have
206           the format "hostname:port:database:username:password". The
207           permissions must permit it to be read only by the user, or the file
208           will not be used.  Only usable with Postgres 8.1 and up.
209
210       PG-PASSWORD
211
212           Password to use when connecting. Deprecated in favor of passfiles.
213
214       PG-PORT
215
216           The TCP port to connect to, or the suffix of the socket file.
217           PostgreSQL defaults to 5432.
218
219       PG-USER
220
221           User to connect as. It must be a superuser.
222
223       PSQL-PATH
224
225           Path to the psql binary. If not specified, the PATH environment
226           variable will be searched.
227

RECOVERY

229       Read the postgres documentation carefully before attempting a recovery.
230       This section is only a rough guide to the process.
231
232       The data recovered from a postgres backup consists of a data tarball
233       and one or more archive tarballs. The data contains the state of the
234       database at the time the full backup was performed, and the archive
235       tarballs contain postgres WAL files that must be re-run to generate a
236       consistent state.
237
238       Ensure that the database server is shut down, and move the existing
239       data directory aside. Untar the data tarball over this directory, and
240       verify that ownership and permissions are correct. Untar all of the
241       archive tarballs into a single directory - the archive directory.
242       Create a recovery.conf in the data directory, owned by the proper user
243       and with proper permissions. Add a restore_command to it, e.g.,
244       restore_command = 'cp /path/to/archive_dir/%f "%p"'
245
246       Start the database server, and examine the logs to track the process of
247       the recovery. When the recovery is complete, the server will transition
248       into a running state, and will move the recovery.conf file aside so
249       that it will not attempt a recovery on the next invocation.
250

EXAMPLE

252       In amanda.conf:
253       define application app_ampgsql {
254         plugin "ampgsql"
255         property "HOST" "localhost"
256         property "ARCHIVEDIR" "/tmp/archivedir"
257         property "PASSFILE" "/etc/amanda/ampgsql.passwd"
258       }
259       define dumptype dump_ampgsql {
260         global
261         program "APPLICATION"
262         application app_ampgsql
263       }
264
265
266       The disklist file:
267         localhost /var/lib/pgsql/data dump_ampgsql
268       or
269         localhost postgres /var/lib/pgsql/data dump_ampgsql
270

SEE ALSO

272       amanda(8), amanda.conf(5), amanda-client.conf(5), amanda-
273       applications(7)
274
275       The Amanda Wiki: : http://wiki.zmanda.com/
276

AUTHOR

278       Nikolas Coukouma <atrus@zmanda.com>
279           Zmanda, Inc. (http://www.zmanda.com)
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283Amanda 3.5.4                      07/27/2023                        AMPGSQL(8)
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