Breaking Up A High Availability Pair

03/26/2020 11 13227

DESCRIPTION:
An administrator could use the following instructions to take a clustered pair of appliances and split them apart into two separate appliances.  Customers who perform this procedure must contact sales to obtain licenses for each node.

RESOLUTION:

Warning  Use the command line at your own risk. SonicWall strongly recommends that users not familiar or comfortable with the command line contact SonicWall product support for assistance. See KB ID SW2500 for some suggestions on enabling SSH access to the appliance and getting onto the command line.

The following steps must be performed on both nodes of the cluster. 

Back up configuration on each appliance

1. From the command line of each appliance, run the following command:
   config_backup
2. Use WinSCP to copy /var/backups/cfgback.tgz from each appliance to your local computer.
3. From AMC on each appliance, navigate to System Configuration | Maintenance | Import or Export | Import/Export and export the configuration of the appliance.  You will download the .aea file to your local computer.

Reconfigure networking

1. Remove the crossover cable from the pair; it will no longer be necessary.

Reset the configuration on each appliance

1. Establish a serial connection to each appliance and issue the following command:
   config_reset
2. After the configuration has been reset, reboot the appliance.
3. When the appliance reboots, log in as root and configure the appliance with enough network information for you to be able to log into AMC.

Import the configuration onto each appliance

1. Now that you have configured AMC for access, log into AMC and configure base networking information: DNS, domain, WINS, routes, and additional interfaces.  Each system should have its own unique IP addresses.
2. Import the configuration (the .aea file) that you saved earlier.
3. Navigate to System Configuration | Maintenance | Import or Export | Import/Export and choose to import a Partial configuration.
4. Apply changes to allow the appliance to load the configuration.

Contingency plan

The cfgback.tgz file saved earlier contains a full configuration of each appliance.  If you decide to revert to the clustered configuration you must perform the following steps:

1. Reconnect the crossover cable between both nodes.
2. Copy cfgback.tgz to /var/log/backups on both nodes.  It should be named cfgback.tgz in that directory.
3. Run the following command to restore the configuration:
   config_restore
4. Reboot the nodes after the configuration restoration.  The appliances should be back to their original states.