HA & Disaster Recovery
To protect your business and ensure that your users have ready access to your servers, you must plan strategies for both high availability and recovery from a hardware failure or natural disaster that could disable your installation.
To determine and implement high availability and disaster recovery solutions, you must first define your business objectives, then purchase and deploy the hardware that is required to achieve those objectives.
High availability (HA) is the measurement of a system’s ability to remain accessible in the event of a system component failure. Generally, HA is implemented by building in multiple levels of fault tolerance and/or load balancing capabilities into a system
High Availability systems seek to minimize two things:
A crucial aspect of high availability is the elimination of single points of failure (SPOFs). A SPOF is an individual piece of equipment or software which will cause system downtime or data loss if it fails. In order to eliminate SPOFs, following mechanisms should be exist for redundancy of :