Manual backup and recovery

This section describes how to make a one-time backup and restore of the files and database. This is useful for rolling back to known-good versions of a service, such as at initial installation and just before an upgrade. First, you back up the database to a file within the file tree. Then, you back up the file tree. All of the information needed to rebuild the site, including the AOLserver config files, is then in tree for regular filesystem backup.

  1. Back up the database to a file. 

    • Oracle. 

      • Download the backup script. Save the file export-oracle.txt as /var/tmp/export-oracle.txt

      • Login as root. The following commands will install the export script:

        [joeuser ~]$ su -
        [root ~]# cp /var/tmp/export-oracle.txt /usr/sbin/export-oracle
        [root ~]# chmod 700 /usr/sbin/export-oracle
      • Setup the export directory; this is the directory where backups will be stored. We recommend the directory /ora8/m02/oracle-exports.

        [root ~]# mkdir /ora8/m02/oracle-exports
        [root ~]# chown oracle:dba /ora8/m02/oracle-exports
        [root ~]# chmod 770 /ora8/m02/oracle-exports
      • Now edit /usr/sbin/export-oracle and change the SERVICE_NAME and DATABASE_PASSWORD fields to their correct values. If you want to use a directory other than /ora8/m02/oracle-exports, you also need to change the exportdir setting.

        Test the export procedure by running the command:

        [root ~]# /usr/sbin/export-oracle
        mv: /ora8/m02/oracle-exports/oraexport-service_name.dmp.gz: No such file or directory
        Export: Release - Production on Sun Jun 11 18:07:45 2000
        (c) Copyright 1999 Oracle Corporation.  All rights reserved.
        Connected to: Oracle8i Enterprise Edition Release - Production
        With the Partitioning option
        JServer Release - Production
        Export done in US7ASCII character set and US7ASCII NCHAR character set
          . exporting pre-schema procedural objects and actions
          . exporting foreign function library names for user SERVICE_NAME 
          . exporting object type definitions for user SERVICE_NAME 
          About to export SERVICE_NAME's objects ...
          . exporting database links
          . exporting sequence numbers
          . exporting cluster definitions
          . about to export SERVICE_NAME's tables via Conventional Path ...
          . exporting synonyms
          . exporting views
          . exporting stored procedures
          . exporting operators
          . exporting referential integrity constraints
          . exporting triggers
          . exporting indextypes
          . exporting bitmap, functional and extensible indexes
          . exporting posttables actions
          . exporting snapshots
          . exporting snapshot logs
          . exporting job queues
          . exporting refresh groups and children
          . exporting dimensions
          . exporting post-schema procedural objects and actions
          . exporting statistics
        Export terminated successfully without warnings.
    • PostgreSQL. Create a backup file and verify that it was created and has a reasonable size (several megabytes).

      [root root]# su - $OPENACS_SERVICE_NAME
      [$OPENACS_SERVICE_NAME $OPENACS_SERVICE_NAME]$ pg_dump -f /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/before_upgrade_to_4.6.dmp $OPENACS_SERVICE_NAME
      [$OPENACS_SERVICE_NAME $OPENACS_SERVICE_NAME]$ ls -al /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/before_upgrade_to_4.6.dmp 
      -rw-rw-r-x    1 $OPENACS_SERVICE_NAME  $OPENACS_SERVICE_NAME   4005995 Feb 21 18:28 /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/before_upgrade_to_4.6.dmp
      [root root]#
      pg_dump -f /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/before_upgrade_to_4.6.dmp openacs-dev
      ls -al /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/before_upgrade_to_4.6.dmp
  2. Back up the filesystem. Back up all of the files in the service, including the database backup file but excluding the auto-generated supervise directory, which is unnecessary and has complicated permissions.

    In the tar command,

    • c create a new tar archive

    • p preserves permissions.

    • s preserves file sort order

    • z compresses the output with gzip.

    • The --exclude clauses skips some daemontools files that are owned by root and thus cannot be backed up by the service owner. These files are autogenerated and we don't break anything by omitting them.

    • The --file clause specifies the name of the output file to be generated; we manually add the correct extensions.

    • The last clause, /var/lib/aolserver/$OPENACS_SERVICE_NAME/, specifies the starting point for backup. Tar defaults to recursive backup.

    [root root]# su - $OPENACS_SERVICE_NAME
    [$OPENACS_SERVICE_NAME $OPENACS_SERVICE_NAME]$ tar -cpsz --exclude /var/lib/aolserver/$OPENACS_SERVICE_NAME/etc/daemontools/supervise \
       --file /var/tmp/$OPENACS_SERVICE_NAME-backup.tar.gz /var/lib/aolserver/$OPENACS_SERVICE_NAME/
    tar: Removing leading `/' from member names
  3. Suffer a catastrophic failure on your production system. (We'll simulate this step)

    [root root]# svc -d /service/$OPENACS_SERVICE_NAME
    [root root]# mv /var/lib/aolserver/$OPENACS_SERVICE_NAME/ /var/lib/aolserver/$OPENACS_SERVICE_NAME.lost
    [root root]# rm /service/$OPENACS_SERVICE_NAME
    rm: remove symbolic link `/service/$OPENACS_SERVICE_NAME'? y
    [root root]# ps -auxw | grep $OPENACS_SERVICE_NAME
    root      1496  0.0  0.0  1312  252 ?        S    16:58   0:00 supervise $OPENACS_SERVICE_NAME
    [root root]# kill 1496
    [root root]# ps -auxw | grep $OPENACS_SERVICE_NAME
    [root root]# su - postgres
    [postgres pgsql]$ dropdb $OPENACS_SERVICE_NAME
    [postgres pgsql]$ dropuser $OPENACS_SERVICE_NAME
    [postgres pgsql]$ exit
    [root root]#
  4. Recovery. 

    1. Restore the operating system and required software. You can do this with standard backup processes or by keeping copies of the install material (OS CDs, OpenACS tarball and supporting software) and repeating the install guide. Recreate the service user ($OPENACS_SERVICE_NAME).

    2. Restore the OpenACS files and database backup file.

      [root root]# su - $OPENACS_SERVICE_NAME
      [$OPENACS_SERVICE_NAME $OPENACS_SERVICE_NAME]$ cd /var/lib/aolserver
      [$OPENACS_SERVICE_NAME aolserver]$ tar xzf /var/tmp/$OPENACS_SERVICE_NAME-backup.tar.gz
      [$OPENACS_SERVICE_NAME aolserver]$ chmod -R 775 $OPENACS_SERVICE_NAME
    3. Restore the database

      • Oracle. 

        1. Set up a clean Oracle database user and tablespace with the same names as the ones exported from (more information).

        2. Invoke the import command

          imp $OPENACS_SERVICE_NAME/$OPENACS_SERVICE_NAME FILE=/var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/nighty_backup.dmp FULL=Y
      • Postgres. If the database user does not already exist, create it.

        [root root]# su - postgres
        [postgres ~]$ createuser $OPENACS_SERVICE_NAME
        Shall the new user be allowed to create databases? (y/n) y
        Shall the new user be allowed to create more new users? (y/n) y
        [postgres ~]$ exit

        Because of a bug in Postgres backup-recovery, database objects are not guaranteed to be created in the right order. In practice, running the OpenACS initialization script is always sufficient to create any out-of-order database objects. Next, restore the database from the dump file. The restoration will show some error messages at the beginning for objects that were precreated from the OpenACS initialization script, which can be ignored.

        [root root]# su - $OPENACS_SERVICE_NAME
        [$OPENACS_SERVICE_NAME ~]$ psql -f /var/lib/aolserver/$OPENACS_SERVICE_NAME/packages/acs-kernel/sql/postgresql/postgresql.sql $OPENACS_SERVICE_NAME
        (many lines omitted)
        [$OPENACS_SERVICE_NAME ~]$ psql $OPENACS_SERVICE_NAME < /var/lib/aolserver/$OPENACS_SERVICE_NAME/database-backup/database-backup.dmp
        (many lines omitted)
        [$OPENACS_SERVICE_NAME ~]$ exit
        [postgres ~]$ exit
    4. Activate the service

      [root root]# ln -s /var/lib/aolserver/$OPENACS_SERVICE_NAME/etc/daemontools /service/$OPENACS_SERVICE_NAME
      [root root]# sleep 10
      [root root]# svgroup web /service/$OPENACS_SERVICE_NAME