CST 334 - Week 7 Journal Entry

This week,I learned understanding of how operating systems control file systems and storage devices, beginning with how the system communicates with input and output devices. I now recognize the crucial functions that interruptions and polling play in device communication. Polling may be time-consuming, particularly for slower devices, as it requires the CPU to continuously check if a device is available. In these situations, interrupts are more effective since they let the CPU focus on other tasks and only react when the device indicates that it is finished. I saw how Direct Memory Access (DMA) enables the device to manage data transport directly, lowering CPU involvement and enhancing system efficiency while transferring large volumes of data. Additionally, I discovered that memory-mapped I/O simplifies communication by enabling device registers to be accessed similarly to memory addresses.

The structure and optimization of disk storage was another subject that caught my attention. Operating systems employ scheduling algorithms to determine the optimal order to handle read and write requests since mechanical components on disks might cause delays. Overall speed and efficiency are increased as a result. RAID systems, which aggregate many drives for improved performance, dependability, or both, were another topic I researched. For instance, striping distributes data across drives for quicker access, while mirroring guarantees data security in the event of a disk failure. Redundancy and performance may be balanced with parity-based RAID.

The final section discussed file systems and the ways in which information is arranged, stored, and retrieved. Structures known as inodes are used to manage files; they hold references to data blocks and information. Directories are unique files that associate inodes with names. There are several backend processes involved in creating or accessing files, such as changing bitmaps, inode tables, and data blocks. I also learnt how write buffering, which groups disk operations, increases efficiency and how caching helps decrease sluggish disk access. All in all, these systems demonstrated to me the complexity and effectiveness of file storage.