Server Contingency Solutions for Highest Availability

D.

Of the offered technologies, load balancing/disk replication offers the highest availability, measured in terms of minutes of lost data or server downtime.

A Network-Attached Storage (NAS) or a Storage Area Network (SAN) solution combined with virtualization would offer an even higher availability.

Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 49).

Among the given server contingency solutions, the one that offers the highest availability is Load balancing/disk replication (option D).

Load balancing is a technique used to distribute workload across multiple servers to ensure that no single server is overloaded. By distributing the workload, the overall system performance is improved, and the risk of server downtime is reduced. In case one server fails, the load can be easily redirected to another server in the pool, ensuring that the system continues to function.

Disk replication, on the other hand, is a process of creating and maintaining an exact copy of data on multiple disks. This technique ensures that if one disk fails, the data can be easily retrieved from the backup disk. With disk replication, the system is always available, and there is minimal downtime in case of disk failure.

System backups (option A) is a process of copying and archiving data, which can be used to restore data in case of system failure. While backups can be useful, they do not offer the same level of availability as load balancing and disk replication.

Electronic vaulting/remote journaling (option B) is a process of transmitting data to a remote location for backup and recovery purposes. While this solution can be useful in case of a disaster, it may not offer the same level of availability as load balancing and disk replication.

Redundant arrays of independent disks (RAID) (option C) is a technique of storing data on multiple disks to improve performance and fault tolerance. RAID can help to prevent data loss in case of disk failure, but it may not offer the same level of availability as load balancing and disk replication.

In conclusion, among the given server contingency solutions, load balancing/disk replication offers the highest level of availability, as it ensures that the system is always available, and there is minimal downtime in case of server or disk failure.