AS 400 Administration Training Program
AS 400 Administration Training Program
1.Module 1:AS/400 Overviews
2.Module 2:System Concepts
3.Module 3:System Administration
4.Module 4:System Security
5.Module 5:Backup and Restoration
Module :- 1
Introducing the AS/400 System :-
The AS/400 system is a family of midrange computers based on a single software architecture.AS/400 is using OS/400 as an operating system. It provides many integrated features that from the foundation of computer systems.
It is designed and built as a total system. It means that facilities such as a relational database and networking capability (and much more) are fully integrated into the Operating System and the machine. The user communicates with all these functions through a single control language, or by using system menus and prompts.As/400 is designed as a general purpose business computer; it is optimized for that environment. Its design reflects the dominant requirements of that environment.
Advantages of As/400 :-
Layered Machine Architecture :- This insulates users from hardware of the system. It enables the users to move towards new hardware technology at any time, without disrupting their application programs.
Object Orientation :- Everything that can be saved or restored on the system is known as an Object. User can find the required object without knowing it`s location on the system. Objects exist to make users independent of the internal structure of the machine.
Single-Level Storage :- Main storage and Disk storage appears contiguous. An object is saved or restored on the system via a device-independent addressing mechanism. This means extra main storage or disk storage can be added to the system and used without affecting the application programs and database. A user or a programmer is not concerned as to where a program or a file is; if they want to use it, they simply name it.
Hierarchy Of Microprocessors :- As well as the main system processor, AS/400 has a large number of microprocessors. Every Input / Output (I/O) device type on AS/400 has its own microprocessor. This means that requests for data to or read from any I/O device can be delegated to the processor in charge of that device. Meanwhile, the main system processor executes another application.
Easy To Use :- From operators and the end users point of view the menu driven structure of AS/400 makes it very easy to operate.
Ability to grow and improve the system without disruption.
AS/400 Hardware :-
Basic Block Diagram OF AS/400 System
The system hardware includes the processor and the main storage, the I/O devices
and controllers, and the racks, cables and controllers that make up the AS/400 system.the hardware design allows system components to be located throughout the enterprise to meet the need of the workplace. System components, such as additional racks, I/O controllers and storage and workstation devices can be added incrementally without reconfiguring the entire system.
Layered Machine Architecture :-
AS/400 insulates users from hardware characteristics through the layered machine architecture. This layered architecture raises the level of the machine interface, creating a high-level machine instruction set is independent of the underlying hardware implementation.
Figure 1 shows the hardware with the licensed internal code that comprises the high-level machine. AS/400 is unusual in that the machine is defined by software, not by hardware. The instructions presented to the machine interface undergo a further process of translation before they are Understood by the hardware. This process of translation is carried out by the licensed internal code. Hardware characteristics change as the technology changes; the user, however, still sees the same interface.
Furthermore, some frequently-executed routines (that would reside in the operating system of a conventional machine) have been moved into licensed internal code. This runs faster than a higher level languages, so any application using these routines will realize a performance gain.
Figure 1 : AS/400 Layered Architecture
Examples of some basic supervisory and resource management functions that are in licensed internal code are validity and authorization checks. The high-level machine provides the user with the ability to address 2^64 bytes of storage on the PowerPc based Models of the As/400.
Layered machine architecture means that as new hardware and software technologies emerge, they can be employed without affecting applications.
The strength of this architecture was evident with the introduction of the new range of PowerPc based AS/400 Models in June 1995. The System Processor changed from being a 48-bit CISC to 64-bit RISC. Yet existing customer applications can run on the new processors and take full advantage of the 64-bit capacity without any recompilation or rewrite needed of the application.Hierarchy Of Microprocessors :-
In As/400 system along with the main system processor, there is a range of other processors, each dedicated to a particular I/O device. What this means is that when the main system processor encounters a request for data to be written to or read from any I/O device, that request is delegated to the particular microprocessor dedicated to that I/O device.Meanwhile, the system processor continues with another application program.
This design provides As/400 with its outstanding performance in the commercial, transaction-based, environment. It also means that the latest microprocessor technology can be easily utilized at any time without disrupting the rest of the system.
Using the N way multiprocessor capability of the As/400, the larger modes of As/400 can have up to 4 processors.
Hierarchy Of MicroprocessorsModule: - 2
Object Oriented Technology :-
Everything on AS/400 that can be stored or retrieved is contained in an Object.
Objects exists to make users independent of the implementation techniques used in the machine. The Create Object instruction establishes the object`s name and its type. All objects are structured with a common object header, and a type-dependent functional portion. An object thus combines the data and the valid methods of using that data into one entity. Therefore only valid methods of using that data are allowed.
This improves overall integrity of the system and its data. Thus also permits the system to perform standard object-level functions very efficiently; the object type then determines the way in which a specific object can be used when retrieved. The architecture supports multiple extends to an object.
In other word, a user is not concerned with the space his object occupies. The system allocates space automatically.
Object orientation gives a strong foundation for new technologies such as artificial intelligence. The object-oriented AS/400 architecture lends itself very well to the utilization of object-oriented techniques for the representation of knowledge in an expert system.
With the PowerPc based Models of the AS/400, the Licensed Internal Code that sits above the hardware has been written as System Licensed Internal Code with an Object Based Kernel. The Kernel has been written in C++ and is fully Object Oriented giving all the advantages of flexibility, code reuse, programming efficiency, and error reduction that come from Object Oriented Programming.
Single Level Storage :-
The AS/400 system is a shared system in which all portions of main and auxiliary storage are addressed as though they are within a single area (or level). The system uses the object name to determine where the object exists in the system. This means that the user can find objects by name rather than by storage locations. Because operations cannot be performed on an objects by name rather than by storage locations. Because operations cannot be performed on an object that is not in main storage, the system moves a part or all of the object into main storage as it is needed and moves it back into auxiliary storage when it is not needed. This transfer is controlled by the system and does not require control by the user or programmer
All system storage (Whether main storage or disk storage) is addressed in the same way. This single, device-independent addressing mechanism means that to run a program, a user calls its name. All objets are treated as if they reside in a 2^ 64 byte address space.
The AS/400 system`s virtual addressing is independent of an object`s physical location, and the type, capacity and number of disk units on the system.
What this means is that application programs do not require modification in order to take advantage of new storage technologies. Users can leave all storage management entirely to the machine.
The OS/400 licensed program supports the IBM AS/400 system. It controls the operation of programs and provides services such as controlling resources, scheduled jobs, controlling input and outputs, and managing data. The OS/400 program is designed to designed to complement and extend the advanced capabilities of the AS/400 system to provide fully integrated support for interactive applications. To supplement the full range of the interactive environment, the AS/400 system also processes multiple batch applications at the same time.
Many of the functions of the OS/400 program are directly applicable to interactive data processing. Among these functions are :
Database support to make up-to-d