Concepts

Business Continuity Division

RPO: (Recovery Point Objective) The point in time to which data must be restored in order to be acceptable to the owner(s) of the processes supported by that data. This is often thought of as the time between the last available backup and the time a disruption could potentially occurs. The RPO is established based on tolerance for loss of data or reentering of data. The RPO in conjunction with the Recovery Time Objective (RTO) is the basis on which data protection strategy is developed.

UPS: (Uninterruptible power systems) A system that provides protection against commercial power failure and variations in voltage and frequency. UPS have a wide variety of applications where unpredictable changes in commercial power will adversely affect equipment. This equipment may include computer installations, telephone exchanges, communications networks, motor and sequencing controls, electronic cash registers, hospital intensive care units, and a host of others. The uninterruptible power system may be used on-line between the commercial power and the sensitive load to provide transient free well-regulated power, or off-line and switched in only when commercial power fails.

NAS: (Network Attached Storage) A specialized file server that connects to the network. A NAS device contains a slimmed-down operating system and a file system and processes only I/O requests by supporting the popular file sharing protocols, primarily CIFS for Windows and NFS for Unix. The NAS concept originated in the early 1990s for computer-aided-design (CAD) and other applications that generated huge data files. File servers with full-blown operating systems have sometimes been called network attached storage, but a true NAS can perform no task other than I/O.

SAN: (Storage Area Network) A network of storage disks. In large enterprises, a SAN connects multiple servers to a centralized pool of disk storage. Compared to managing hundreds of servers, each with their own disks, SANs improve system administration. By treating all the company's storage as a single resource, disk maintenance and routine backups are easier to schedule and control. In some SANs, the disks themselves can copy data to other disks for backup without any processing overhead at the host computers.

FT: (Fault Tolerance) The ability to continue non-stop when a hardware failure occurs. A fault-tolerant system is designed from the ground up for reliability by building multiples of all critical components, such as CPUs, memories, disks and power supplies into the same computer. In the event one component fails, another takes over without skipping a beat.

HA: (High Availability) it refers to a multiprocessing system that can quickly recover from a failure. There may be a minute or two of downtime while one system switches over to another, but processing will continue. This is not the same as fault tolerant, in which redundant components are designed for continuous processing without skipping a heartbeat.

RTO: (Recovery Time Objective) The amount of time a computer system or application can stop functioning before it is considered intolerable to the enterprise. It can be computed to be from seconds to days, depending on how critical the application is to the organization. The RTO is used to determine the types of backup and disaster recovery plans that should be implemented. See backup types and disaster recovery.