The simplest case is that the structure of a DR system mirrors exactly the structure of the LIVE system. That means that in the DR system, you have exactly the same servers and other resources (disks, SANs, network) as on the LIVE system.

DR system is stand-by while the LIVE system is producing.

When a disaster happens, there are steps to perform on the LIVE system (assuming it's not completely destroyed), and on the DR system. Details of such steps depend on the structure of the LIVE and of the DR system.

In the real-life situation, the DR systems often has less servers than the LIVE systems, so the functionalities, spread on the LIVE servers are not exactly the same as on the DR servers.

Again, have in mind that this document give you just an example.

Assumed structure of the LIVE system

We assume there are four servers on the LIVE system:

1. L-GN4Web server with the World Wide Web Publishing Service

2. L-GN4Back4 server with the Tera Back4 service and the volume replication Windows Scheduled Task

3. L-GN4SQL server with the SQL Server Agent (MSSQLSERVER) Service that replicates data from the "Live" server to the "DR" server

4. L-GN4Index server with the Exalead Cloudview service

Assumed structure of the DR system

We assume there are four servers on the LIVE system:

1. DR-GN4Web server with the World Wide Web Publishing Service

2. DR-GN4Back4 server with the Tera Back4 service and the volume replication Windows Scheduled Task

3. DR-GN4SQL server with the SQL Server Agent (MSSQLSERVER) Service that replicates data from the "Live" server to the "DR" server

4. DR-GN4Index server with the Exalead Cloudview service

Note

All the LIVE server names are here marked with the L- prefix, while all DR servers are marked with DR prefix. Such naming convention is arbitrary.

How to understand on which server (DR or LIVE) you are?

To make it easier to differentiate between the live servers from the DR servers, you can use the windows background color. For example, you can set it to blue on the live servers and green on the DR servers.

How to find the DR-related files?

We recommend that you save all the DR-related batch files, in a specific (and the same) folder on each server, e.g. "C:\Tera\DR. Moreover, it is recommended that you provide a desktop icon "DR" that opens the DR folder.