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