Brandon's Weekly Learning Journal

 Week 8, This final week served as a recap for all the things we learned in the second half of the course. With both concurrency and persistence. However, I would like to continue to talk about persistence as it was a very dense topic. Last week, I had briefly talked about some of the things that were covered in the material, but not why they were important. As everyone knows, hard drives or solid-state drives are important. They hold data for our applications, photos, videos, etc. It is common for people to view it simply as storage, which it is to be fair, but really it should be viewed as a way for the computer to remember things after it is shut down, or a process finishes a task. We want data to persist. When the computer shuts down, it forgets a lot of data, including the OS. When the computer turns on again, it grabs the OS from the hard drive and loads it in the main memory. The hard drive's control block contains information about how data is stored on it, which allows the...

 Week 7, This week's topic covers persistence, more specifically, persistent storage. First we read about I/O devices and how they work. This includes the DMI, eSATA/SATA and USB, and how they can connect to an I/O chip to communicate to the CPU. This is important especially considering this is how we connect storage devices like hard drives. After learning more about how the hard drive works by spinning the disk and reading and writing to it using the disk arm and head as well as the important things stored in it such as the superblock, inodes, bitmap, and data region. To put everything briefly, there is a lot that goes on under the hood when it comes to reading and writing to the hard drive, with a large amount of effort being used to decide how to read/write to better optimize for performance, capacity, or persistence. After figuring that out, we also talked about file systems, which allows the OS to manage data on a hard drive or other I/O devices. There are different ways to d...