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Appendix C. Migrating Databases and Services to a Remote Server

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Although you cannot configure remote databases and services during the automated installation, you can migrate them to a separate server post-installation.

C.1. Migrating the Data Warehouse to a Separate Machine

This section describes how to migrate the Data Warehouse database and service from the Red Hat Virtualization Manager machine to a separate machine. Hosting the Data Warehouse service on a separate machine reduces the load on each individual machine, and avoids potential conflicts caused by sharing CPU and memory resources with other processes.

Note

Red Hat only supports installing the Data Warehouse database, the Data Warehouse service and Grafana all on the same machine as each other, even though you can install each of these components on separate machines from each other.

You have the following migration options:

  • You can migrate the Data Warehouse service away from the Manager machine and connect it with the existing Data Warehouse database (ovirt_engine_history).
  • You can migrate the Data Warehouse database away from the Manager machine and then migrate the Data Warehouse service.

C.1.1. Migrating the Data Warehouse Database to a Separate Machine

Migrate the Data Warehouse database (ovirt_engine_history) before you migrate the Data Warehouse service. Use engine-backup to create a database backup and restore it on the new database machine. For more information on engine-backup, run engine-backup --help.

Note

Red Hat only supports installing the Data Warehouse database, the Data Warehouse service and Grafana all on the same machine as each other, even though you can install each of these components on separate machines from each other.

The new database server must have Red Hat Enterprise Linux 8 installed.

Enable the required repositories on the new database server.

C.1.1.1. Enabling the Red Hat Virtualization Manager Repositories

You need to log in and register the Data Warehouse machine with Red Hat Subscription Manager, attach the Red Hat Virtualization Manager subscription, and enable the Manager repositories.

Procedure

  1. Register your system with the Content Delivery Network, entering your Customer Portal user name and password when prompted:

    # subscription-manager register
    Note

    If you are using an IPv6 network, use an IPv6 transition mechanism to access the Content Delivery Network and subscription manager.

  2. Find the Red Hat Virtualization Manager subscription pool and record the pool ID:

    # subscription-manager list --available
  3. Use the pool ID to attach the subscription to the system:

    # subscription-manager attach --pool=pool_id
    Note

    To view currently attached subscriptions:

    # subscription-manager list --consumed

    To list all enabled repositories:

    # dnf repolist
  4. Configure the repositories:

    # subscription-manager repos \
        --disable='*' \
        --enable=rhel-8-for-x86_64-baseos-eus-rpms \
        --enable=rhel-8-for-x86_64-appstream-eus-rpms \
        --enable=rhv-4.4-manager-for-rhel-8-x86_64-rpms \
        --enable=fast-datapath-for-rhel-8-x86_64-rpms \
        --enable=jb-eap-7.4-for-rhel-8-x86_64-rpms \
        --enable=openstack-16.2-cinderlib-for-rhel-8-x86_64-rpms \
        --enable=rhceph-4-tools-for-rhel-8-x86_64-rpms \
        --enable=rhel-8-for-x86_64-appstream-tus-rpms \
        --enable=rhel-8-for-x86_64-baseos-tus-rpms
  5. Set the RHEL version to 8.6:

    # subscription-manager release --set=8.6
  6. Enable version 12 of the postgresql module.

    # dnf module -y enable postgresql:12
  7. Enable version 14 of the nodejs module:

    # dnf module -y enable nodejs:14
  8. Update the Self-Hosted Engine using the procedure Updating a Self-Hosted Engine in the Upgrade Guide.

Additional resources

For information on modules and module streams, see the following sections in Installing, managing, and removing user-space components

C.1.1.2. Migrating the Data Warehouse Database to a Separate Machine

Procedure

  1. Create a backup of the Data Warehouse database and configuration files on the Manager:

    # engine-backup --mode=backup --scope=grafanadb --scope=dwhdb --scope=files --file=file_name --log=log_file_name
  2. Copy the backup file from the Manager to the new machine:

    # scp /tmp/file_name root@new.dwh.server.com:/tmp
  3. Install engine-backup on the new machine:

    # dnf install ovirt-engine-tools-backup
  4. Install the PostgreSQL server package:

    # dnf install postgresql-server postgresql-contrib
  5. Initialize the PostgreSQL database, start the postgresql service, and ensure that this service starts on boot:

    # su - postgres -c 'initdb'
    # systemctl enable postgresql
    # systemctl start postgresql
  6. Restore the Data Warehouse database on the new machine. file_name is the backup file copied from the Manager.

    # engine-backup --mode=restore --scope=files --scope=grafanadb --scope=dwhdb --file=file_name --log=log_file_name --provision-dwh-db

    When the --provision-* option is used in restore mode, --restore-permissions is applied by default.

The Data Warehouse database is now hosted on a separate machine from that on which the Manager is hosted. After successfully restoring the Data Warehouse database, a prompt instructs you to run the engine-setup command. Before running this command, migrate the Data Warehouse service.

C.1.2. Migrating the Data Warehouse Service to a Separate Machine

You can migrate the Data Warehouse service installed and configured on the Red Hat Virtualization Manager to a separate machine. Hosting the Data Warehouse service on a separate machine helps to reduce the load on the Manager machine.

Notice that this procedure migrates the Data Warehouse service only.

To migrate the Data Warehouse database (ovirt_engine_history) prior to migrating the Data Warehouse service, see Migrating the Data Warehouse Database to a Separate Machine.

Note

Red Hat only supports installing the Data Warehouse database, the Data Warehouse service and Grafana all on the same machine as each other, even though you can install each of these components on separate machines from each other.

Prerequisites

  • You must have installed and configured the Manager and Data Warehouse on the same machine.
  • To set up the new Data Warehouse machine, you must have the following:

    • The password from the Manager’s /etc/ovirt-engine/engine.conf.d/10-setup-database.conf file.
    • Allowed access from the Data Warehouse machine to the Manager database machine’s TCP port 5432.
    • The username and password for the Data Warehouse database from the Manager’s /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/10-setup-database.conf file.

      If you migrated the ovirt_engine_history database using the procedures described in Migrating the Data Warehouse Database to a Separate Machine, the backup includes these credentials, which you defined during the database setup on that machine.

Installing this scenario requires four steps:

  1. Setting up the New Data Warehouse Machine
  2. Stopping the Data Warehouse service on the Manager machine
  3. Configuring the new Data Warehouse machine
  4. Disabling the Data Warehouse package on the Manager machine

C.1.2.1. Setting up the New Data Warehouse Machine

Enable the Red Hat Virtualization repositories and install the Data Warehouse setup package on a Red Hat Enterprise Linux 8 machine:

  1. Enable the required repositories:

    1. Register your system with the Content Delivery Network, entering your Customer Portal user name and password when prompted:

      # subscription-manager register
    2. Find the Red Hat Virtualization Manager subscription pool and record the pool ID:

      # subscription-manager list --available
    3. Use the pool ID to attach the subscription to the system:

      # subscription-manager attach --pool=pool_id
    4. Configure the repositories:

      # subscription-manager repos \
          --disable='*' \
          --enable=rhel-8-for-x86_64-baseos-eus-rpms \
          --enable=rhel-8-for-x86_64-appstream-eus-rpms \
          --enable=rhv-4.4-manager-for-rhel-8-x86_64-rpms \
          --enable=fast-datapath-for-rhel-8-x86_64-rpms \
          --enable=jb-eap-7.4-for-rhel-8-x86_64-rpms
      
      # subscription-manager release --set=8.6
  2. Enable the pki-deps module.

    # dnf module -y enable pki-deps
  3. Ensure that all packages currently installed are up to date:

    # dnf upgrade --nobest
  4. Install the ovirt-engine-dwh-setup package:

    # dnf install ovirt-engine-dwh-setup

C.1.2.2. Stopping the Data Warehouse Service on the Manager Machine

Procedure

  1. Stop the Data Warehouse service:

    # systemctl stop ovirt-engine-dwhd.service
  2. If the database is hosted on a remote machine, you must manually grant access by editing the postgres.conf file. Edit the /var/lib/pgsql/data/postgresql.conf file and modify the listen_addresses line so that it matches the following:

    listen_addresses = '*'

    If the line does not exist or has been commented out, add it manually.

    If the database is hosted on the Manager machine and was configured during a clean setup of the Red Hat Virtualization Manager, access is granted by default.

  3. Restart the postgresql service:

    # systemctl restart postgresql

C.1.2.3. Configuring the New Data Warehouse Machine

The order of the options or settings shown in this section may differ depending on your environment.

  1. If you are migrating both the ovirt_engine_history database and the Data Warehouse service to the same machine, run the following, otherwise proceed to the next step.

    # sed -i '/^ENGINE_DB_/d' \
            /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/10-setup-database.conf
    
    # sed -i \
         -e 's;^\(OVESETUP_ENGINE_CORE/enable=bool\):True;\1:False;' \
         -e '/^OVESETUP_CONFIG\/fqdn/d' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
  2. Remove the apache/grafana PKI files, so that they are regenerated by engine-setup with correct values:

    # rm -f \
      /etc/pki/ovirt-engine/certs/apache.cer \
      /etc/pki/ovirt-engine/certs/apache-grafana.cer \
      /etc/pki/ovirt-engine/keys/apache.key.nopass \
      /etc/pki/ovirt-engine/keys/apache-grafana.key.nopass \
      /etc/pki/ovirt-engine/apache-ca.pem \
      /etc/pki/ovirt-engine/apache-grafana-ca.pem
  3. Run the engine-setup command to begin configuration of Data Warehouse on the machine:

    # engine-setup
  4. Press Enter to accept the automatically detected host name, or enter an alternative host name and press Enter:

    Host fully qualified DNS name of this server [autodetected host name]:
  5. Press Enter to automatically configure the firewall, or type No and press Enter to maintain existing settings:

    Setup can automatically configure the firewall on this system.
    Note: automatic configuration of the firewall may overwrite current settings.
    Do you want Setup to configure the firewall? (Yes, No) [Yes]:

    If you choose to automatically configure the firewall, and no firewall managers are active, you are prompted to select your chosen firewall manager from a list of supported options. Type the name of the firewall manager and press Enter. This applies even in cases where only one option is listed.

  6. Enter the fully qualified domain name and password for the Manager. Press Enter to accept the default values in each other field:

    Host fully qualified DNS name of the engine server []: engine-fqdn
    Setup needs to do some actions on the remote engine server. Either automatically, using ssh as root to access it, or you will be prompted to manually perform each such action.
    Please choose one of the following:
    1 - Access remote engine server using ssh as root
    2 - Perform each action manually, use files to copy content around
    (1, 2) [1]:
    ssh port on remote engine server [22]:
    root password on remote engine server engine-fqdn: password
  7. Enter the FQDN and password for the Manager database machine. Press Enter to accept the default values in each other field:

    Engine database host []: manager-db-fqdn
    Engine database port [5432]:
    Engine database secured connection (Yes, No) [No]:
    Engine database name [engine]:
    Engine database user [engine]:
    Engine database password: password
  8. Confirm your installation settings:

    Please confirm installation settings (OK, Cancel) [OK]:

The Data Warehouse service is now configured on the remote machine. Proceed to disable the Data Warehouse service on the Manager machine.

C.1.2.4. Disabling the Data Warehouse Service on the Manager Machine

Prerequisites

  • The Grafana service on the Manager machine is disabled:

    # systemctl disable --now grafana-server.service

Procedure

  1. On the Manager machine, restart the Manager:

    # service ovirt-engine restart
  2. Run the following command to modify the file /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf and set the options to False:

    # sed -i \
         -e 's;^\(OVESETUP_DWH_CORE/enable=bool\):True;\1:False;' \
         -e 's;^\(OVESETUP_DWH_CONFIG/remoteEngineConfigured=bool\):True;\1:False;' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
    
    # sed -i \
         -e 's;^\(OVESETUP_GRAFANA_CORE/enable=bool\):True;\1:False;' \
         /etc/ovirt-engine-setup.conf.d/20-setup-ovirt-post.conf
  3. Disable the Data Warehouse service:

    # systemctl disable ovirt-engine-dwhd.service
  4. Remove the Data Warehouse files:

    # rm -f /etc/ovirt-engine-dwh/ovirt-engine-dwhd.conf.d/*.conf /var/lib/ovirt-engine-dwh/backups/*

The Data Warehouse service is now hosted on a separate machine from the Manager.

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