We have already seen how the Network Operating System (NOS) provides support for many devices, users, functionalities and a special class of computer called a server. What are the different server platforms? The answers to this may surprise because in essence there really are not that many different classes of server platforms.
Mainframe Server Platform
Mainframe computer platform; also referred to as “Big Iron” are computers that are predominantly used by very large organizations for “mission critical” applications. The early mainframe computers were very large machines in deed, occupying entire rooms and in some cases many floors of a building.
Now the term is primarily used to refer to the ultra high-end computer as opposed to less well endowed computers. Mainframe computer is now generally meant to include computers that are compatible with the IBM System/360 series (first introduced in 1965). Other very high-end computers that are not compatible with the IBM System/360 series are usually referred to as “servers”.
The major distinguishing feature of the modern mainframe computer is their considerable amount of redundant internal engineering. This gives these mainframe computers high reliability, tight security, extensive input/output facilities, strict backwards compatibility for older software, and high utilization rates (very little processing idle time) to support their characteristic massive throughput capabilities.
These mainframe computers usually run for many years without interruption. All repairs and hardware upgrades take place during normal operation of the mainframe computer which is another benefit that the inclusion of internal redundant hardware engineering makes possible.
The tasks that these mainframe computers usually perform today still revolve around the so called “mission critical” operations that require much repetative or parallel processing such as correlation of data collected during a census or a survey, statistical processing and analysis, financial transaction processing (banks) and Enterprise Resource Planning (ERP).
By the way, the computational power of the mainframe class computer platform is measured in terms of Millions of Instructions Per Second (MIPS).
Above all else it is their reliability that defines and identifies the mainframe class of computer platform with uninterrupted service histories measured in many numbers of years. Many of the current IBM mainframe computers have been working non-stop for over a decade now. Not bad value for the dollar.
One last aspect of the mainframe computer platform that I will touch on here is their ability to run or host not just one operating system at a time, but many. In this way a single mainframe computer can replace tens or even hundreds of smaller servers. In so doing administrative and management costs are greatly reduced yet at the same time still providing for superior scalability and reliability.
Now to the smaller server platform. I will start with the generally smaller standard server platform known as “stand alone” or bastion host servers.
Bastion Host Server Platform
The “stand alone” or bastion host server platform is very similar to your average “stand alone” tower workstation or desktop PC, which they may in fact very well be. More robust servers, containing multiple redundant hardware components, especially redundant power supply units (PSU) and hard disk drives (HDD) occupy considerably more space and generally consume more energy.
As far as the average small business or community group is concerned, the small bastion host server has more than enough compute power and resources to service their needs. This is truer today more than ever before with the current generation of multi-core CPUs and high capacity storage devices making it possible for a tower to perform server platform functionalities.
Both the hard disk drive (HDD) and optical disk (usually DVD) are now more than capable of satisfying the small players' computational storage requirements. The streamlined backup and restore procedures offered by today's network operating systems is better than ever and the automation capability of these services is now better than ever before.
It is no surprise to find that many multi-core “consumer” type workstations are currently finding their way into service as a server platform by much of the community both for business and for personal use scenarios alike.
I will now briefly mention the classic bastion host server. This class of server computer platform is characterised by their multiplicity of redundant hardware components. Multiple redundant power supplies (PSU) being one of the more common components that are duplicated in this class of server platform.
Others include support for multiple multi-core CPUs, vast memory array support, multiple internal hard disk drive (HDD) bays, duplicate and even in some instances an array of optical storage drives (usually DVD-R and DVD-RW) and numerous network interface modules supporting high-end network transport media such as Gigabit and 10 Gigabit Ethernet as well as fiber-optic transmission media.
