Local Area VAXcluster
Citations from "AA-JP20C-TE VMS Local Area VAXcluster Manual":
- Using Ethernet as the common interconnect, Local Area VAXcluster Software extends many benefits of the VAXcluster architecture to MicroVAX II, MicroVAX 2000, VAXstation II, and VAXstation 2000 systems.
- A single Ethernet may support multiple Local Area VAXcluster configurations, each identified and secured by a unique group number and a cluster password.
- A Local Area VAXcluster configuration consists of one or two boot nodes and up to 26 satellite nodes.
- A boot node is both a management center for the cluster and a major resource provider. Its system disk contains the cluster common files for startup, authorization, and queue setup, as well as the directory roots from which the satellite nodes are booted.
- A boot node makes available to the cluster such resources as user and application data disks, printers, and distributed batch processing facilities.
- The satellite nodes are booted remotely from a boot node's system disk. Generally, these nodes are consumers of cluster resources, though they may also sometimes provide disk serving and batch processing resources. If satellite nodes are equipped with disks, they may, for enhanced performance, use such local disks for paging and swapping.
Later on (beginning with the VMS V5.x era), the term "boot node" was differentiated into boot server (providing boot services) and disk server (providing access to Cluster-wide mass storage). It was recommended to use dedicated VAXserver systems for these purposes, although you could use any VAX computer proving enough power.
Local Area VAXcluster preconditions
In a Local Area VAXcluster configuration, a boot node may be any VAX system except VAX-11/725 or VAX-11/730, or it may be a MicroVAX or VAXstation systems, except for MicroVAX I, VAXstation I, MicroVAX 2000, and VAXstation 2000. Special (VMS version specific) restrictions apply for boot node minimum memory and available disk space, which may limit the number of supported satellites.
Neither the MicroVAX I nor the VAXstation I were supported as satellites because of hardware limitations (boot ROM and memory).