-
-Chapter 15. How to use a wrapper
-Prev Part III. HOWTOs Next
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-
-Chapter 15. How to use a wrapper
-
-
-Bert de Ridder
-
-Original text
-
-Paul Bijnens
-
-Original text
-
-Stefan G. Weichinger
-
-XML-conversion; Updates
-AMANDA Core Team
-<sgw@amanda.org>
-Table of Contents
-
-
- Bert_de_Ridder's_suggestions
-
- Paul_Bijnens's_suggestions
-
-
-Note
-
-Refer to http://www.amanda.org/docs/howto-wrapper.html for the current version
-of this document.
-
-Note
-
-The script used in this document is not part of the official Amanda release.
-The Amanda core team does not take any responsibility for this script.
-
-Bert de Ridder's suggestions
-
-This is a mini-howto explaining how to control other running tasks on a server
-where the Amanda software is used to backup data.
-Problem : Lots of software is picky about their datafiles being backed up while
-the files are in use. It sometimes is even necessary to know the state of the
-datafiles at the moment of backup so that when restoring you know exactly
-*what* you are restoring. And most of the time there are dependencies between
-the datafiles as well (for instance, the pure datafiles and the controlfiles of
-an Oracle database.)
-The solution is actually quite simple; you just use a custom made backupscript
-instead of the standard tar command. Inside this tar command, you do some
-necessary processing before executing the tar command and - if necessary - do
-some more processing. This way, you can easily stop an Oracle database, tar the
-files, send them to the tape server and restart the Oracle database. This of
-course is just an example, anything you can do in a shell script can be done.
-
- 1. Create the script
- This is the most important step, this script is the work horse of the
- solution. I've called it /bin/amandatar. You can call it whatever you want
- though. It's a Perl script, it may not be very pretty code, but it does
- the job. In the script, an example is given for the backup of a Lotus
- Notes Domino server.
-
- #!/usr/bin/perl
-
- # Tar wrapper for Amanda's tar.
- #
-
- use Getopt::Long qw(:config pass_through);
-
- # Obtain directory and file information from the command line.
-
- $result = GetOptions (
- 'directory=s' => \$dir,
- 'file=s' => \$file
- );
-
- # Check whether Amanda wants to do some administrative task (eg.
- indexinfo
- # or obtain the number of bytes to be backed up)
- # if file = /dev/null it's an administrative task and most of the time,
- no extra
- # processing is necessary.
-
- # What you see here is just a log of the backup start time, and \96 more
- important
- # the stopping of the domino server
-
- if ( $file ne '/dev/null' )
- {
- if ( $dir eq '/local/notesdata' )
- {
- system "echo 'Start backup notes at ' >> /var/lib/amanda/runtime" ;
- system "date >> /var/lib/amanda/runtime";
- system ( "/etc/init.d/domino stop >> /var/lib/amanda/runtime" );
- }
- }
-
- # The command line is being 'reconstructed'. Necessary because the
- GetOptions
- # call above has stripped the file and directory information.
- # This is what I meant with 'ugly' code ;-)
-
- while ( $ARGV[0] ne '' )
- {
- $val = $ARGV[0] ;
- unshift ( @NEWARGV, $val, ) ;
- shift @ARGV;
- }
-
- while ( $NEWARGV[0] ne '' )
- {
- $val = $NEWARGV[0] ;
- unshift ( @ARGV, $val ) ;
- shift @NEWARGV;
- }
-
- if ( $dir ne '' )
- {
- unshift ( @ARGV, '--directory', $dir );
- }
- if ( $file ne '' )
- {
- unshift ( @ARGV, '--file', $file );
- }
-
- if ( $file ne '/dev/null' )
- {
- system "echo 'Backing up directory ' $dir >> /var/lib/amanda/runtime"
- ;
- }
-
- # And finally make sure tar is called :-)
- # (path may differ on your installation)
- unshift ( @ARGV , "/bin/tar" ) ;
-
- system ( @ARGV ) ;
-
- # Postprocessing
- #
- # If Notes backup was requested, restart the server.
- # Log the backup end time.
- #
-
- if ( $file ne '/dev/null' )
- {
- if ( $dir eq '/local/notesdata' )
- {
- system ( "/etc/init.d/domino start >> /var/lib/amanda/runtime" );
- system "echo 'End backup notes at ' >> /var/lib/amanda/runtime" ;
- system "date >> /var/lib/amanda/runtime";
- }
- }
-
- exit 0;
-
- # End script
-
- On some systems it may be necessary to setuid root the script.
- 2. Rebuild Amanda so that it uses your newly created script.
- Download the sources, untar them to a directory. I'm sure there are lots
- of documents already available on how to do this, so I won't go into too
- much detail. (Refer to Amanda_Installation_Notes).
- fast path :
-
- /usr/local/src # tar -xvzf amanda-source.tar.gz
- /usr/local/src # cd amanda-version
- /usr/local/src/amanda-version # ./configure \
- --with-user=amanda \
- --prefix=/usr/local \
- --exec-prefix=/usr \
- --bindir=/usr/bin \
- --sbindir=/usr/sbin \
- --libexecdir=/usr/lib/amanda \
- --with-configdir=/etc/amanda \
- --with-group=disk \
- --with-gnutar=/bin/amandatar \
- --with-gnutar-listdir=/var/lib/amanda/gnutar-lists \
- --with-tmpdir=/tmp/amanda \
- --with-smbclient=/usr/bin/smbclient \
- --mandir=/usr/local/man
-
- Here, it may be necessary to adjust some paths to match your installation.
- This setup works on SuSE Linux (also SLES) and MacOSX although you may
- have to use another binary tar.
- As you see, you may also "replace" the smbclient if necessary. I haven't
- yet tested it though. I'll leave it as an exercise for the reader <g>.
-
- /usr/local/src/amanda-version # make
- /usr/local/src/amanda-version # make install
-
- Now proceed as with a "normal" installation.
-
-
-Paul Bijnens's suggestions
-
-How do I run pre- and post dump programs, e.g. database stop/start?
-Currently (Amanda 2.4.5) there is no direct support to run a program before or
-after a backup on a client. But there is an easy workaround by using a wrapper
-for GNU-tar that does the additional tasks.
-Let's suppose you want to stop a database before the backup, and start it up
-again when the backup is finished. You have already two scripts "shutdb" and
-"startdb" to shutdown and startup the database.
-First you have to configure Amanda on the client to use the gnutar-wrapper
-instead of the real GNU-tar:
-
- ./configure ... --with-gnutar=/usr/local/bin/amgtar ...
-
-and re-compile Amanda. The program "amgtar" can be a simple link to the real
-GNU-tar-binary on clients that don't need special handling, or it can be a
-script.
-Amanda expects that the bytestream on stdout is the backup image, and the
-bytestream on stderr are messages. The stderr messages are filtered against a
-known set of strings, and anything unexpected is flagged as "STRANGE" in the
-Amanda report. The return-codes of the program should be the same as the
-return-codes of GNU-tar:
-
-* 0 = ok (backup image will be put on tape)
-* 1 = not ok (backup image will not be put on tape, same level will be tried
- next time).
-
-The arguments passed to the program are pretty static (see in the sources
-client-src/sendbackup-gnutar.c, line 483). To decide if you need to stop/start
-the database you have to check if:
-
-* this run makes a backup and not a restore: look for "--create"
-* this it is not an estimate run: look for "--file /dev/null" (estimate) or "--
- file -" (real run)
-* this run is for the database directory: look for "--directory /my/data/base"
-
-In all other cases, we just pass the args and run the real GNU-tar.
-Here is an example script in Bourne shell:
-Example 15.1.
-
- #!/bin/sh
-
- # # uncomment next block to follow the flow
- # LOG=/tmp/amanda/mytar.debug
- # date >> $LOG
- # echo "$@" >> $LOG
- # if [ "$3" = "/dev/null" ]
- # then echo "Estimate only" >> $LOG
- # else echo "Real backup" >> $LOG
- # fi
-
- # - Avoid output to stdout! (the backup stream by tar)
- # - Any output to stderr is flagged as "strange" by amanda
- # and may be used to pass error messages into the report
-
- if [ "$1" = "--create" -a "$3" = "-" -a "$5" = "/my/dir" ]
- then
- # echo "/my/dir: want to execute some progs first" >>$LOG
- /usr/local/bin/shutdb thedb >&2
- /usr/local/bin/gtar "$@"
- rc=$?
- # echo "Finished the real backup; some postprocessing" >>$LOG
- /usr/local/bin/startdb thedb >&2
- exit $rc
- else
- /usr/local/bin/gtar "$@"
- fi
-
-
-Here is an example script in perl:
-Example 15.2.
-
- #!/usr/bin/perl -w
-
- use Getopt::Long qw(:config pass_through);
-
- my @saveopts = @ARGV;
- GetOptions (
- 'create' => \$create,
- 'directory=s' => \$dir,
- 'file=s' => \$file,
- );
- @ARGV = @saveopts;
-
- my $postproc = 0;
- if ($create && $dir eq '/my/data/base' && $file ne '/dev/null') {
- system '/usr/local/bin/dbshut thedb >/tmp/amanda/dbshut.debug 2>&1';
- $postproc = 1;
- }
-
- unshift(@ARGV, "/usr/local/bin/gtar");
- system @ARGV;
-
- my $rc = $? >> 8;
-
- if ($postproc) {
- system '/usr/local/bin/dbstart thedb >/tmp/amanda/dbstart.debug 2>&1';
- }
-
- exit $rc;
-
-
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