CST 334 - Week 7

Week 7 Summary:

This week in CST 334, I learned in depth about how file systems are organized on disk and how they are accessed by the operating system. The lectures broke file systems into two main parts: the on-disk data structures (like the superblock, inodes, data blocks, and bitmaps) and the access methods used to navigate those structures to find and read files. I now have a much clearer picture of how the superblock acts as a “map” to the file system, pointing to where the inode region and data blocks begin, and how inodes store file metadata and pointers to data blocks. Bitmaps turned out to be an efficient way of tracking which inodes and blocks are free or used, reducing the need to scan every single block. We also discussed how files use direct, single indirect, and double indirect pointers to scale up file sizes, and how directories are simply files with structured data that map names to inode numbers. In the access portion of the lectures, I learned the step-by-step process for resolving a path like /foo/bar, starting from the root inode and walking through directory entries until reaching the final file’s inode and reading its data blocks. This connected directly to some of our quiz questions, where I had to count disk I/Os needed to resolve and read files. The practice problems also reinforced how to calculate seek delay, rotational delay, transfer time, and total disk access time for multiple reads. I also worked with VSFS simulations, identifying what filesystem operation (like create, link, or unlink) took place between two states by analyzing changes in the inode and data bitmaps. These exercises gave me a much better grasp of the relationship between high-level file operations and the low-level structures they modify.