 |
LAN recovery provides a readily available backup server which will take over operations when the active server or application fails.
Recovery over a LAN is often simpler and faster than WAN recovery as bandwidth and connectivity issues do not come in to play in the same way as they would for a WAN solution. As such, it is often used as a first phase towards a WAN solution.
All servers used can be active, there is no need for a redundant server, and servers do not need to be similar, or paired in any way.
WAN recovery provides a readily available backup server at a remote site which will take over operations when the active server or application fails.
Data is replicated between the server, as for the LAN solution, and the application and its dependencies are monitored, when there is a disruption in service detected, the users transfer over to the backup server.
The 3node solution replicates to both a local and backup server. This may sound like an expensive luxury, but LifeKeeper supports many-to-one failover so that many servers can replicate to one backup. Virtual environments make the organization of physical servers more flexible in that multiple physical servers can be used to failover to virtual server.
It is difficult to say exactly how much downtime has been saved by the LifeKeeper clustering solution but we have maintained uninterrupted service during events that would otherwise could have caused hours of downtime. With the reassurance and failover that LifeKeeper provides we have also been able to perform system maintenance and upgrades without affecting end users.
Chris Good, M-Spatial
