Chapter 12. Backups and Migration

Procedure 12.1. Example Usage of the engine-backup Command

1. Log on to the machine running the Red Hat Enterprise Virtualization Manager.
2. Create a backup:

   Example 12.1. Creating a Full Backup

   # engine-backup --scope=all --mode=backup --file=file_name --log=log_file_name

   Example 12.2. Creating a Manager Database Backup

   # engine-backup --scope=files --scope=db --mode=backup --file=file_name --log=log_file_name

   Replace the db option with dwhdb or reportsdb to back up the Data Warehouse database or the Reports database.
   A tar file containing a backup is created using the path and file name provided.

Procedure 12.2. Restoring a Backup to a Fresh Installation

1. Log on to the machine on which the Red Hat Enterprise Virtualization Manager is installed. If you are restoring the engine database to a remote host, you will need to log on to and perform the relevant actions on that host. Likewise, if also restoring Reports and the Data Warehouse to a remote host, you will need to log on to and perform the relevant actions on that host.
2. Restore a complete backup or a database-only backup.
   • Restore a complete backup:

     # engine-backup --mode=restore --file=file_name --log=log_file_name --provision-db --no-restore-permissions

     If Reports and Data Warehouse are also being restored as part of the complete backup, provision the additional databases:

     engine-backup --mode=restore --file=file_name --log=log_file_name --provision-db --provision-reports-db --provision-dwh-db --no-restore-permissions

   • Restore a database-only backup by restoring the configuration files and database backup:

     # engine-backup --mode=restore --scope=files --scope=db --file=file_name --log=log_file_name --provision-db --no-restore-permissions

     The example above restores a backup of the Manager database.

     # engine-backup --mode=restore --scope=files --scope=reportsdb --file=file_name --log=log_file_name --provision-reports-db --no-restore-permissions

     The example above restores a backup of the Reports database.

     # engine-backup --mode=restore --scope=files --scope=dwhdb --file=file_name --log=log_file_name --provision-dwh-db --no-restore-permissions

     The example above restores a backup of the Data Warehouse database.
   If successful, the following output displays:

   You should now run engine-setup.
   Done.

3. Log on to the Manager machine. Run the following command and follow the prompts to configure the restored Manager:

   # engine-setup

Procedure 12.3. Restoring a Backup to Overwrite an Existing Installation

1. Log on to the machine on which the Red Hat Enterprise Virtualization Manager is installed.
2. Run the following command and follow the prompts to remove the configuration files for and clean the database associated with the Manager:

   # engine-cleanup

3. Restore a full backup or a database-only backup:
   • Restore a full backup:

     # engine-backup --mode=restore --file=file_name --log=log_file_name

   • Restore a database-only backup by restoring the configuration files and the database backup:

     # engine-backup --mode=restore --scope=files --scope=db --file=file_name --log=log_file_name

     The example above restores a backup of the Manager database. If necessary, also restore the Reports and Data Warehouse databases:

     # engine-backup --mode=restore --scope=reportsdb --scope=dwhdb --file=file_name --log=log_file_name

   If successful, the following output displays:

   You should now run engine-setup.
   Done.

4. Run the following command and follow the prompts to reconfigure the firewall and ensure the ovirt-engine service is correctly configured:

   # engine-setup

Procedure 12.4. Restoring a Backup with Different Credentials

1. Log on to the machine on which the Red Hat Enterprise Virtualization Manager is installed.
2. Run the following command and follow the prompts to remove the configuration files for and clean the database associated with the Manager:

   # engine-cleanup

3. Change the password for the owner of the engine database if the credentials of that user are not known:
   1. Enter the postgresql command line:

      # su postgres
      $ psql

   2. Change the password of the user that owns the engine database:

      postgres=# alter role user_name encrypted password 'new_password';

      Repeat this for the users that own the ovirt_engine_reports and ovirt_engine_dwh databases if necessary.
4. Restore a complete backup or a database-only backup with the --change-db-credentials parameter to pass the credentials of the new database. The database_location for a database local to the Manager is localhost.

   Note

   The following examples use a --*password option for each database without specifying a password, which will prompt for a password for each database. Passwords can be supplied for these options in the command itself, however this is not recommended as the password will then be stored in the shell history. Alternatively, --*passfile=password_file options can be used for each database to securely pass the passwords to the engine-backup tool without the need for interactive prompts.
   • Restore a complete backup:

     # engine-backup --mode=restore --file=file_name --log=log_file_name --change-db-credentials --db-host=database_location --db-name=database_name --db-user=engine --db-password

     If Reports and Data Warehouse are also being restored as part of the complete backup, include the revised credentials for the two additional databases:

     engine-backup --mode=restore --file=file_name --log=log_file_name --change-db-credentials --db-host=database_location --db-name=database_name --db-user=engine --db-password --change-reports-db-credentials --reports-db-host=database_location --reports-db-name=database_name --reports-db-user=ovirt_engine_reports --reports-db-password --change-dwh-db-credentials --dwh-db-host=database_location --dwh-db-name=database_name --dwh-db-user=ovirt_engine_history --dwh-db-password
     

   • Restore a database-only backup by restoring the configuration files and the database backup:

     # engine-backup --mode=restore --scope=files --scope=db --file=file_name --log=log_file_name --change-db-credentials --db-host=database_location --db-name=database_name --db-user=engine --db-password

     The example above restores a backup of the Manager database.

     # engine-backup --mode=restore --scope=files --scope=reportsdb --file=file_name --log=log_file_name --change-reports-db-credentials --reports-db-host=database_location --reports-db-name=database_name --reports-db-user=ovirt_engine_reports --reports-db-password

     The example above restores a backup of the Reports database.

     # engine-backup --mode=restore --scope=files --scope=dwhdb --file=file_name --log=log_file_name --change-dwh-db-credentials --dwh-db-host=database_location --dwh-db-name=database_name --dwh-db-user=ovirt_engine_history --dwh-db-password

     The example above restores a backup of the Data Warehouse database.
   If successful, the following output displays:

   You should now run engine-setup.
   Done.

5. Run the following command and follow the prompts to reconfigure the firewall and ensure the ovirt-engine service is correctly configured:

   # engine-setup

Procedure 12.5. Preparing the Remote PostgreSQL Database for use with the Red Hat Enterprise Virtualization Manager

1. Log in to the remote database server and install the PostgreSQL server package:

   # yum install postgresql-server

2. Initialize the PostgreSQL database, start the postgresql service, and ensure that this service starts on boot:

   # service postgresql initdb
   # service postgresql start
   # chkconfig postgresql on

3. Connect to the psql command line interface as the postgres user:

   # su - postgres
   $ psql

4. Create a user for the Manager to use when it writes to and reads from the database. The default user name on the Manager is engine:

   postgres=# create role user_name with login encrypted password 'password';

   Note

   The password for the engine user is located in plain text in /etc/ovirt-engine/engine.conf.d/10-setup-database.conf. Any password can be used when creating the role on the new server, however if a different password is used then this file must be updated with the new password.
5. Create a database in which to store data about the Red Hat Enterprise Virtualization environment. The default database name on the Manager is engine, and the default user name is engine:

   postgres=# create database database_name owner user_name template template0 encoding 'UTF8' lc_collate 'en_US.UTF-8' lc_ctype 'en_US.UTF-8';
   

6. Ensure the database can be accessed remotely by enabling md5 client authentication. Edit the /var/lib/pgsql/data/pg_hba.conf file, and add the following line immediately underneath the line starting with local at the bottom of the file, replacing X.X.X.X with the IP address of the Manager:

   host    database_name    user_name    X.X.X.X/32   md5

7. Allow TCP/IP connections to the database. Edit the /var/lib/pgsql/data/postgresql.conf file and add the following line:

   listen_addresses='*'

   This example configures the postgresql service to listen for connections on all interfaces. You can specify an interface by giving its IP address.
8. Open the default port used for PostgreSQL database connections, and save the updated firewall rules:

   # iptables -I INPUT 5 -p tcp --dport 5432 -j ACCEPT
   # service iptables save

9. Restart the postgresql service:

   # service postgresql restart

Procedure 12.6. Migrating the Database

1. Log in to the Red Hat Enterprise Virtualization Manager machine and stop the ovirt-engine service so that it does not interfere with the engine backup:

   # service ovirt-engine stop

2. Create the engine database backup using the PostgreSQL pg_dump command:

   # su - postgres -c 'pg_dump -F c engine -f /tmp/engine.dump'

3. Copy the backup file to the new database server. The target directory must allow write access for the postgres user:

   # scp /tmp/engine.dump root@new.database.server.com:/tmp/engine.dump

4. Log in to the new database server and restore the database using the PostgreSQL pg_restore command:

   # su - postgres -c 'pg_restore -d engine /tmp/engine.dump'

5. Log in to the Manager server and update the /etc/ovirt-engine/engine.conf.d/10-setup-database.conf and replace the localhost value of ENGINE_DB_HOST with the IP address of the new database server. If the engine name, role name, or password differ on the new database server, update those values in this file.
6. Now that the database has been migrated, start the ovirt-engine service:

   # service ovirt-engine start