Configuring Hot Standby Redundancy

Configuring redundancy involves the following tasks:

A. Obtain all the information that you will need for the procedures.
See Information Needed to Configure Hot Standby Redundancy.

B. Ensure that all required appliances are installed.
See Ensuring All Required Appliances Are Installed.

C. Perform basic configuration of all appliances at both sites.
See Basic Appliance Configuration.

D. Copy the license file for redundancy to both sites.
See Copying the License File to Both Sites.

E. Configure and start the redundancy.
See Configuring and Starting Redundancy.

CAUTION: Please carefully read and adhere to the following regulations. Failure to do so may result in the improper functioning of the Hot Standby Redundancy system:

1. Redundancy control commands MUST ONLY be executed on one site at a time.
2. Ensure that all redundancy control command operations (such as start, stop, restart, etc.) are fully completed before performing any other actions.
3. Contact our technical support team if any unexpected errors occur.

Information Needed to Configure Hot Standby Redundancy

Basic Appliance Configuration for Hot Standby Redundancy

Ensuring All Required Appliances Are Installed

You must ensure that all appliances required at Site-A and Site-B have been installed and are connected to the network.

If you are setting up redundancy for an existing Legacy orchestrator system, you will need to install the required appliance(s) at the additional site.

If you are moving from a Warm Standby setup to a Hot Standby setup, note that the database of the second site will be wiped out when Hot Standby Redundancy is enabled.

For detailed information about installing appliances, see:

• VMware Virtual Machine Installation and Connectivity
• KVM Virtual Machine Installation and Connectivity

Accessing the Appliance Console

All procedures must be performed in the console of the appliance being configured. You can connect to the console of an appliance in one of these ways:

• Use an SSH client
• Access the console of a virtual appliance from the host

The procedures must be executed as the visionems user. You must know the account credentials.

Basic Appliance Configuration

The following table summarizes the basic configuration that is required on all appliances at both sites. It also gives you links to the relevant configuration procedures in this guide or other manuals.

Basic Appliance Configuration for Hot Standby Redundancy

The basic configuration must have been done on all appliances. All procedures must be performed on newly installed appliances. Certain procedures can be skipped on previously installed appliances. The number of appliances that must be configured depends on the installation scenario:

• If you are setting up a second site for an existing Legacy orchestrator system consisting of a single Legacy orchestrator appliance, you must configure the appliance at the new site only.
• If both sites are new installations and each site only includes a single Legacy orchestrator appliance, you must configure both appliances.

Copying the License File to Both Sites

The redundancy feature requires a license. The license must be available on the appliances on both sites so that you can import it during the procedure in the next section.

You will need an SCP client (such as WinSCP) on your computer.

1. Obtain the license file from Accedian Technical Support and save to your computer.

2. Copy the license file to Site-A:
   a. Use the SCP client and the visionems account to access the Legacy orchestrator appliance for Site-A.
   b. Copy the redundancy license file from your computer to the /data directory on the appliance for Site-A.

3. Copy the license file to Site-B:
   a. Use the SCP client and the visionems account to access the Legacy orchestrator appliance for Site-B.
   b. Copy the redundancy license file from your computer to the /data directory on the appliance for Site-B.

4. If you are not already logged in on the appliance console, log in as the visionems user.
   The prompt is displayed.
   

   ---

   Note: Perform this procedure in the console of the Legacy orchestrator appliance for Site-B.

   ---

5. Import the license for the redundancy feature by entering:
   redundancy license import filename fullPath/licenseFilename
   Example of full path and filename: /data/drbd-proxy.license

6. If you are not already logged in on the appliance console, log in as the visionems user.
   The prompt is displayed.
   

   ---

   Note: This procedure is performed in the console of the Legacy orchestrator appliance for Site-A.

   ---

7. Import the license for the redundancy feature by entering:
   redundancy license import filename fullPath/licenseFilename
   Example of full path and filename: /data/drbd-proxy.license

Configuring and Starting Redundancy

The procedures in this section cover all the tasks required to configure and start the redundancy feature, this procedure needs to be executed on Site-A only.
You will need to set the preferred site, including:

• Configure the virtual IP
• Start the redundancy feature
• Test that the redundancy feature is operating normally.

To configure redundancy

1. Configure redundancy by entering these commands:
   redundancy config site-a hostname nameSiteA
   redundancy config site-a replication-ip a.a.a.a
   redundancy config site-a monitor-ip c.c.c.c
   where:
   nameSiteA is the hostname that was previously assigned to the appliance of Site-A.
   a.a.a.a is the address of the interface previously configured for data replication.
   c.c.c.c is the address of the interface previously configured for monitoring.

CAUTION: You must configure and activate redundancy on Site-A. The configuration will be automatically replicated to Site-B.

2. Configure redundancy by entering these commands, and provide Site-B details:
   redundancy config site-b hostname nameSiteB
   redundancy config site-b monitor-ip b.b.b.b
   redundancy config site-b replication-ip d.d.d.d
   where:
   nameSiteB is the hostname that was previously configured for the appliance at Site-B
   b.b.b.b is the address of the interface previously configured for data replication
   d.d.d.d is the address of the interface previously configured for monitoring

3. If you want to designate the preferred site (this will be the active site at startup and after recovery from a failover), enter:
   redundancy config preferred siteOption
   where:
   siteOption is your choice of preferred site. Possible values: none (default), site-a, site-b

4. Configure the virtual IP for the Legacy orchestrator system as follows:

Note: By default, the virtual IP state is enabled.

If the user needs to configure the virtual IP, they must follow the two steps below.

a. Set the virtual IP address by entering:
redundancy config virtual-ip vip-address e.e.e.e
where:
e.e.e.e is the virtual IP address (previously configured for the Legacy orchestrator system)

b. Configure the primary interface associated with virtual IP address:
redundancy config virtual-ip vip-primary-interface ethX
where:
ethX is the primary interface (previously configured for the virtual IP address)

If the user does not need to configure the virtual IP, enter:
redundancy config virtual-ip vip-state disable

CAUTION: The next step (disabling auto-failover) is NOT recommended. For more information, see Disabling Automatic Failover.

5. If you want to disable automatic failover, enter:
   redundancy config auto-failover disable
6. Display the redundancy configuration by entering:
   redundancy show configuration
   The configuration should be similar to the following:

7. Start the redundancy feature by entering:
   redundancy control start
   After a short delay, redundancy becomes operational and the prompt is displayed. If a preferred site has been set, it is the active site. If preferred site is set to none (default value), Site-A is the active site. Data is being replicated from the active site to the passive site. Connectivity between the two sites is being monitored.

8. Check whether the redundancy feature is operating normally by entering:
   redundancy test
   The test checks that redundancy is configured properly and that data replication is taking place. The results are displayed.

Disabling Automatic Failover

By default, redundancy is configured with automatic failover enabled. The system will determine when it is necessary to switch from the active to the passive site and will do so without human intervention.

If you prefer to decide when to fail over from the active site to the passive site, you can change the redundancy configuration to disable automatic failover. If you disable automatic failover, replication and monitoring will continue. It will be necessary to manually switch from the active site to the passive site in the event of a failure on the active site. See the redundancy control switch command in Controlling Redundancy.

If you decide to disable automatic failure, we recommend that you do so during the initial configuration of redundancy. See Configuring and Starting Redundancy.

To change the automatic failover configuration

If you decide to disable automatic failover after redundancy has been started, you can do so as explained in this procedure. You can do this on the appliance at Site-A.

1. If you are not already logged in on the appliance console, log in as the visionems user.

2. Stop the redundancy feature by entering:
   redundancy control stop

3. Ensure that redundancy has been stopped by entering:
   redundancy show status
   The output should indicate that the global status is Stopped.

4. To disable the automatic failover configuration, enter:
   redundancy config auto-failover disable

5. Ensure that redundancy configuration has changed by entering:
   redundancy show configuration
   The output should indicate that auto-failover has been Disabled.

6. Start the redundancy feature by entering:
   redundancy control start

7. Ensure that redundancy has been started by entering:
   redundancy show status
   The output should indicate that the global status is Started.