CS Learning Journal

  WELCOME TO WEEK 8 Learning Journal This week in CST 334, I learned about the concept of persistence as it applies to operating systems. In computer science, persistence refers to the ability of a system's state to outlive the process that created it, which is important for ensuring data is stored and remains accessible even after the process ends. This is done by storing data in permanent storage like disks or RAIDs. Understanding how persistence works at the system level will help me design more reliable software that can effectively manage data. On a personal level, persistence is also a key trait for me as a CST 334 SCD Online student. Just as an operating system needs to maintain data despite challenges, I need to stay persistent in my studies, continuing to push forward even when faced with difficulties. This really important for completing this course and achieving my long-term academic and professional goals. 

  WELCOME TO WEEK 7 Learning Journal      This week we learned about the main form of persistent data storage in computer systems, which are hard disk drives. The drives consist of sectors that can be read or written. These sectors are numbered 0 to n-1 on a disk with n sectors. They can be viewed as an array of sectors. In order to read or write from the sectors, we use the disk head and arm. The surface of the disk rotates counterclockwise. To understand how a request would be processed, the disk just has to wait for the desired sector to rotate under the disk head. This is what is called rotational delay. However, there are multiple tracks on the disk, and it will seek along the rotations. This will be the seek time. Finally, once it is in the desired sector, the final phase of I/O will be the transfer, where data will either be read or written to the surface. Therefore, the I/O time would be represented by three major components: seek time, rotational delay, and transfer time. It i