File Access Method
There are three ways to access a file into a computer system: Sequential-Access, Direct Access, Index sequential Method. In Sequential Access, Information in the file is processed in order, one record after the other. The direct access is based on the disk model of a file since disk allows random access to any file block. For direct access, the file is viewed as a numbered sequence of block or record. The Indexed Access method is built on the top of the direct access method. These methods construct an index for the file.
FIle System Organization
File Organization refers to the logical relationships among various records that constitute the file, particularly with respect to the means of identification and access to any specific record. In simple terms, Storing the files in certain order is called file Organization.
File System
File system is the part of the operating system which is responsible for file management. It provides a mechanism to store the data and access to the file contents including data and programs. Some Operating systems treats everything as a file for example Ubuntu.
File System Structure
File System provide efficient access to the disk by allowing data to be stored, located and retrieved in a convenient way. A file System must be able to store the file, locate the file and retrieve the file.
Memory Bus
The memory bus connects the memory system and the northbridge area of the chipset. This section of the chipset also connects directly to the central processing unit and the graphics system. While this means the northbridge is the center of many important computer functions, it is actually the computer’s memory that determines the bus’s speed.
Central Processing Unit
A central processing unit is generally the most important component in a computer system. It is primarily responsible for the lion’s share of the computation and data handling that go on inside a computer. The only common exceptions are certain graphics-related calculations, which are commonly handled by additional processing units installed on video cards. The central processing unit is the main component on a computer that determines how fast a system runs.
Memory-mapped IO vs Port-mapped IO
Microprocessors normally use two methods to connect external devices: memory mapped or port mapped I/O. Memory mapped I/O is mapped into the same address space as program memory and/or user memory, and is accessed in the same way. Port mapped I/O uses a separate, dedicated address space and is accessed via a dedicated set of microprocessor instructions.
Clustered Systems
The clustered systems are a combination of hardware clusters and software clusters. The hardware clusters help in sharing of high performance disks between the systems. The software clusters makes all the systems work together.
Spooling in Operating System
Spooling stands for “Simultaneous Peripheral Operations Online”. So, in a Spooling, more than one I/O operations can be performed simultaneously i.e. at the time when the CPU is executing some process then more than one I/O operations can also de done at the same time.
Pipelining
Pipelining is the process of accumulating instruction from the processor through a pipeline. Pipelining is a technique where multiple instructions are overlapped during execution. Pipeline is divided into stages and these stages are connected with one another to form a pipe like structure.