Norsk Data A/S, Oslo, Norway, has introduced a high availability configuration of its ND 32- and 16-bit minis, the ND-FTX. By no means a full fault-tolerant system, it nevertheless offers a master-slave CPU arrangement, support for mirrored disks, and automatic switching of peripherals – without any changes to existing applications software. The facility, which can be added in the field, provides automatic duplication of text and data to up to 16 pairs disk drives, under control of the ND-Sibas database manager. Restart can be in as little as one or two seconds, the rate being set by the frequency of checkpointing by Sibas. The slave can be used for non-critical work as it monitors the master; in the event of failure it switches disks, terminals and lines over to itself.
