bionic (8) ampgsql.8.gz

Provided by: amanda-common_3.5.1-1ubuntu0.3_amd64 bug

NAME

       ampgsql - Amanda Application to interface with PostgreSQL

DESCRIPTION

       Ampgsql is an Amanda Application API script. It should not be run by users directly. It implements
       on-line backups of PostgreSQL databases in conjunction with WAL archiving.

           Note
           Tablespaces are not currently supported.

           Note
           On versions of PostgreSQL earlier than 8.2, if the database is quiet during a full backup, then the
           backup may not complete until enough database activity takes place to trigger the archiving of the
           current WAL file. Consider adjusting the PG-MAX-WAL-WAIT property from its default (60s) to
           compensate. Note that you will need to increase dtimeout on the server accordingly.

DISKLIST

       The diskdevice must be the cluster data directory, if it is "/var/lib/pgsql/data":
         HOST DISKNAME /var/lib/pgsql/data DUMPTYPE
       or
         HOST /var/lib/pgsql/data DUMTYPE

OPERATION

       This application implements the backup strategy described in
       http://www.postgresql.org/docs/current/static/continuous-archiving.html. For a level zero (full) backup,
       ampgsql:

       •   execute PG_START_BACKUP()

       •   dump the data directory

       •   execute PG_STOP_BACKUP()

       •   wait for the final WAL file to be archived

       •   back up the required WAL files

       •   optionally delete WAL files that are no longer necessary

       The two dumps are made with GNU Tar, to data_dir.tar and archive_dir, respectively. They are then
       combined into a single tar file.

       A level N backup creates a single tar file containing all WAL files since the previous level N-1 backup.

PROPERTIES

       This section lists the amanda.conf(5) properties that control ampsql's functionality. See amanda-
       applications(7) for information on application properties and how they are configured.

       ARCHIVEDIR
           Directory that WAL segment files are archived to, as specified by the archive_command in PosgreSQL's
           postgresql.conf. The amanda user on the client must have at least read and execute permission on this
           directory, and preferably write. Without write permission, Amanda cannot clean up expired WAL and
           backup files.

       CLEANUPWAL
           Whether or not to remove old WAL segment files during base backups. Defaults to yes.

       DB
           Database to connect to. Defaults to "template1" (which exists by default).

       DIRECTORY
           For restore command only, the data is recoved in that directory. Must be a unix path.

       FULL-WAL
           Which WAL files to archive when doing a full backup.

           FULL
               Backup all WAL files since the previous full backup.

           INCR
               Backup all WAL files since the previous backup (incr or full).

           NO
               Backup all WAL files required for that full backup

           The default is "INCR".

       GNUTAR-PATH
           Path to the GNU tar executable. This option only has an effect during restore. The default is set
           when Amanda is built by the --with-gnutar configure option.

       HOST
           Host to connect to. If it starts with "/" it will be interepreted as a directory that holds the
           socket file. PostgreSQL defaults to /tmp.

       INCREMENTAL
           Default: NO. If set to "YES", then backup only the WAL files since the previous backup.

           It reduce the size of the backup, but amanda will not be able to restore all incrementals, the
           restore must be done manually.It is easier to set the dumptype bump* parameter to force a bump at
           every backup.

       MAX-WAL-WAIT
           The maximum amount of time to wait for PG_STOP_BACKUP to archive a WAL file. In versions of
           PostgreSQL before 8.2, PG_STOP_BACKUP does not automatically archive the latest WAL file, so a quiet
           database may wait a very long time before archiving the WAL file. Default: 60 seconds. Set to 0 to
           wait forever.

       PASSFILE
           Connect using the creditials in this file. Each line should have the format
           "hostname:port:database:username:password". The permissions must permit it to be read only by the
           user, or the file will not be used. Only usable with Postgres 8.1 and up.

       PORT
           The TCP port to connect to, or the suffix of the socket file. PostgreSQL defaults to 5432.

       PSQL-PATH
           Path to the psql binary. If not specified, the PATH environment variable will be searched.

       REMOVE-FULL-WAL
           Default: YES. Remove all WAL files included in the full backup.

       REMOVE-INCREMENTAL-WAL
           Default: NO. If set to "YES" then remove all WAL files included in the incremental backup.

       STATEDIR
           Directory for saving state about backups already made. The default is set when Amanda is built by the
           --with-gnutar-listdir configure option.

       TMPDIR
           Directory to use for temporary files during the backup process. It should have enough space to store
           a complete copy of the database. The default is set when Amanda is built by the --with-tmpdir
           configure option.

       USER
           User to connect as. It must be a superuser.

       VERBOSE
           Do not use the --quiet output of psql.

CLIENT PROPERTIES

       Client properties are deprecated. All properties should be set in the dumptype.

       This section lists the amanda-client.conf(5) properties that control ampsql's functionality. If a
       property is prefixed with the diskname and an underscore, then it will be used when that diskname is
       being backed up. For example, if the properties PG-DATADIR and foo-PG-DATADIR are set, the value of
       PG-DATADIR will be used when bar and baz are being backed up, but foo-PG-DATADIR will be used when foo is
       being backed up. Disknames are specified in the disklist(5).

       PG-ARCHIVEDIR

           Directory that WAL segment files are archived to, as specified by the archive_command in PosgreSQL's
           postgresql.conf.  The amanda user on the client must have at least read and execute permission on
           this directory, and preferably write.  Without write permission, Amanda cannot clean up expired WAL
           and backup files.

       PG-CLEANUPWAL

           Whether or not to remove old WAL segment files during base backups.  Defaults to yes.

       PG-DATADIR

           Cluster data directory

       PG-DB

           Database to connect to. Defaults to "template1" (which exists by default).

       PG-HOST

           Host to connect to. If it starts with "/" it will be interepreted as a directory that holds the
           socket file. PostgreSQL defaults to /tmp.

       PG-MAX-WAL-WAIT
           The maximum amount of time to wait for PG_STOP_BACKUP to archive a WAL file. In versions of
           PostgreSQL before 8.2, PG_STOP_BACKUP does not automatically archive the latest WAL file, so a quiet
           database may wait a very long time before archiving the WAL file. Default: 60 seconds. Set to 0 to
           wait forever.

       PG-PASSFILE

           Connect using the creditials in this file. Each line should have the format
           "hostname:port:database:username:password". The permissions must permit it to be read only by the
           user, or the file will not be used.  Only usable with Postgres 8.1 and up.

       PG-PASSWORD

           Password to use when connecting. Deprecated in favor of passfiles.

       PG-PORT

           The TCP port to connect to, or the suffix of the socket file. PostgreSQL defaults to 5432.

       PG-USER

           User to connect as. It must be a superuser.

       PSQL-PATH

           Path to the psql binary. If not specified, the PATH environment variable will be searched.

RECOVERY

       Read the postgres documentation carefully before attempting a recovery. This section is only a rough
       guide to the process.

       The data recovered from a postgres backup consists of a data tarball and one or more archive tarballs.
       The data contains the state of the database at the time the full backup was performed, and the archive
       tarballs contain postgres WAL files that must be re-run to generate a consistent state.

       Ensure that the database server is shut down, and move the existing data directory aside. Untar the data
       tarball over this directory, and verify that ownership and permissions are correct. Untar all of the
       archive tarballs into a single directory - the archive directory. Create a recovery.conf in the data
       directory, owned by the proper user and with proper permissions. Add a restore_command to it, e.g.,
       restore_command = 'cp /path/to/archive_dir/%f "%p"'

       Start the database server, and examine the logs to track the process of the recovery. When the recovery
       is complete, the server will transition into a running state, and will move the recovery.conf file aside
       so that it will not attempt a recovery on the next invocation.

EXAMPLE

       In amanda.conf:
       define application app_ampgsql {
         plugin "ampgsql"
         property "HOST" "localhost"
         property "ARCHIVEDIR" "/tmp/archivedir"
         property "PASSFILE" "/etc/amanda/ampgsql.passwd"
       }
       define dumptype dump_ampgsql {
         global
         program "APPLICATION"
         application app_ampgsql
       }

       The disklist file:
         localhost /var/lib/pgsql/data dump_ampgsql
       or
         localhost postgres /var/lib/pgsql/data dump_ampgsql

SEE ALSO

       amanda(8), amanda.conf(5), amanda-client.conf(5), amanda-applications(7)

       The Amanda Wiki: : http://wiki.zmanda.com/

AUTHOR

       Nikolas Coukouma <atrus@zmanda.com>
           Zmanda, Inc. (http://www.zmanda.com)