From Computer History Wiki
Jump to: navigation, search

VAXservers are VAX servers (not for interactive time-sharing usage) which share many components with other VAX models. Lines include:

Hardware Differences

The main difference between a VAXserver model and its VAX/MicroVAX pendant was the ROM on the CPU board.

Further differences exist in the equipment with options and peripheral devices. For example, VAXservers always had (for obvious reasons) an Ethernet network adapter.

Typical Usage

One of the prime uses of VAXserver computers was to act as boot and disk servers for Local Area VAXclusters (LAVC).

Another important use was as a "Compute Server", e.g. as a dedicated machine for batch processing large jobs, particularly in VAXclusters, where one could simply send a batch job to another cluster member as if the batch queue was on the local machine.


Recommandations from AA-LA27B-TE VMS VAXcluster Manual VMS V5.4:

As a general rule, use as boot and disk servers the most powerful computers in the cluster. Low-powered computers can become overloaded when serving many busy satellites, or when many satellites boot simultaneously. Note, however, that two or more moderately powered servers can provide better performance than a single high-powered server.
Multiple servers give better availability, and they distribute the workload across more Ethernet adapters. If you have several computers of roughly comparable power, it is reasonable to use them all as boot servers. This arrangement gives optimal load balancing. In addition, if one computer fails or is shut down, others remain available to serve satellites.
After compute power, the most important factor in selecting a server is the speed of its Ethernet adapter. Servers should be equipped with the highest-bandwith Ethernet adapters in the cluster.

If there was already a multi-user VAX or a "big" VAXcluster (CI/DSSI) with free capacity, you usually didn't buy an additional VAXserver. However, if the existing VAXes were already busy or a new LAVC was being set up, then VAXservers were the first choice. A lot of money could be saved by using VAXservers instead of multi-user VAXes, since the costs for the operating system licenses were much lower.

See also