For many organizations, a loss of service is just as devastating as a loss of information. The odds of service interruption or information loss decrease significantly if no single points of failure exist. Some interesting and powerful technologies exist that can keep mission-critical services available even in the face of a catastrophic disaster.
- Recovering from a network catastrophe takes time.
- Sooner or later, a major system failure will happen.
- A truly redundant information system contains no single points of failure.
- Maintaining high availability becomes more difficult and more expensive as systems increase in size.
Ensuring availability is a challenge for any organization, large or small. There is much more to ensuring availability than making sure data is backed up. The following chapters cover a variety of methods to help keep data ready and waiting at all times:
- RAID introduces technique for using multiple synchronized hard
drives to increase performance and/or reliability.
- Clustering describes a technology that allows a system to remain
operational if its hardware or software fails by replicating its running processes on a simultaneous system in real time.
- Backup Systems actually perform two functions, copying critical
data to another location and enabling the swift and painless recovery of the backed up data.
- Distributed Computing (web bonus) is used to obtain unprecedented power, availability and capacity by getting many machines to work together on a problem.
- Rollout Systems (web bonus) explores tools that enable updates or installations to occur over networks, to many nodes at the same time.