everRun Extend Disaster Recovery: enabling application fault tolerance across sites connected via a WAN, using asynchronous replication
everRun Extend disaster recovery technology keeps your systems fully mirrored in real time synchronisation to a second DR site. When disaster strikes the second site simply takes over from the primary site. This solution can be deployed as a standalone DR solution for small yet critical single server sites or can be combined with Stratus fault tolerant solutions (everRun / ftServer / ztCEdge) combining local system redundancy with WAN based disaster recovery by maintaining a hot standby system located in a remote site.
Disasters, whether caused by nature, mechanical or power failures, or human error can result in the total loss of all computing resources in a facility - potentially leaving your business unable to function for days or even weeks. everRun Extend disaster recovery can help prevent that.
How everRun Extend fits with everRun / ftServer / ztC Edge
The Stratus fault tolerant solutions are the products that protect customers from server failures or other system/network component failures. everRun Extend disaster recovery provides rapid recovery from total site outages. The most typical configuration is one where customers have a fault tolerant solution in a primary site and a Windows system running on a single physical machine in the DR site. everRun Extend keeps data at the DR site synchronised with the primary site to provide DR failover to the second site should the unthinkable happen (also called the Master and Replica sites). Some customers also have a fault tolerant system at the DR site to ensure high availability / fault tolerance after a disaster recovery scenario is executed.
everRun Extend disaster recovery software is Windows based and is installed in the Windows environment to protect the applications running within that system. It is a complementary and layered product in the fault tolerant product suite.
everRun Extend also gets installed in a Windows sytem at the remote DR site. This can be a Windows system running on a physical machine, multiple Windows systems running standard Hypervisors (VMWare / Hyper V) or a Windows system/s running in Protected Virtual Machine/s (PVM) on an everRun, ftServer or ztC Edge platform.
Three configurations are possible:
- V2P: the primary site has an application running in an everRun PVM and the DR site has the application running on Windows system in a physical machine.
- V2V: Both sites have the application running in a VM (everRun / VMware or Hyper V).
- P2P: Both sites have the application running in a Windows system running on a physical machine with no fault tolerance at the primary site - ie, a standalone solution without the use of any other Stratus products.
During normal processing, everRun Extend disaster recovery software performs real time and immediate asynchronous replication of all application data between the primary site and the DR site. The primary site runs the active application. The DR siste does not run the application and is simply being kept up to date in order to be able to take over from the primary site when needed.
When the primary site has a complete failure, everRun Extend will execute a DR scenario which brings the DR site up on the network with the identity of the primary site and starts the application using up to date copies of the data.