DG/UX
| Industry | Computer software |
|---|---|
| Founded | 1968 |
| Products | DG/UX |
DG/UX was a now-obsolete Unix operating system created by Data General initially for its Eclipse MV minicomputer series, and subsequently adapted for the AViiON workstation and server platforms, which included both Motorola 88000 and Intel IA-32 architectures.
Overview
By the mid-1980s, numerous computer manufacturers had introduced Unix as an alternative to their proprietary operating systems. Launched in March 1985, DG/UX version 1.00 was derived from UNIX System V Release 2 and incorporated features from 4.1BSD. Two years later, DG/UX 3.10 integrated advanced networking capabilities such as 4.2BSD TCP/IP, NFS, and the X Window System. The release of DG/UX 4.00 in 1988 marked a significant overhaul, built upon System V Release 3, adding support for symmetric multiprocessing on Eclipse MV machines and employing a filesystem influenced by the AOS/VS II design that could manage multiple disks simultaneously. Around 1991, DG/UX 5.4 introduced a unified demand-paged virtual memory system that replaced the traditional Unix file buffer cache, with subsequent versions evolving from System V Release 4.
On AViiON platforms, DG/UX provided multiprocessor support at a time when many other Unix variants lacked such functionality. It came equipped with a complete C compiler (gcc) and incorporated a logical volume manager. The operating system was both compact and feature-dense, offering straightforward installation and efficient operation; for instance, a six-processor Pentium Pro AViiON system could accommodate hundreds of users connected through text-based terminals.
Its integrated volume manager allowed administrators to perform disk management tasks—such as extending, relocating, mirroring, or reducing volumes—without taking filesystems offline. These capabilities extended to swap partitions, enabling live storage migrations without service interruptions. Features like filesystem shrinking, "split mirror" online backups, support for filesystems up to 2 TB in size, and journaling were available as early as 1991 in DG/UX 5.4—functionality uncommon among competitors at that time.
DG/UX also implemented a high-performance clustered filesystem utilizing high-voltage SCSI controllers and hubs through Clariion storage NAS solutions. Each server was outfitted with dual SCSI controllers to provide failover protection; both controllers operated as bus masters simultaneously while filesystems were NFS-mounted via the cluster-master's floating IP address. Data transfers occurred directly over SCSI from individual cluster nodes, with inode table management handled through NFS mounts.
Subsequent versions introduced processor and memory affinity features designed to enhance performance on advanced multiprocessor NUMA AViiON configurations.