CST334 - Week 7 Reflection

        This week of CST334 saw the class exploring file system implementation, low-level storage performance, and file system-related system calls. The lab work on persistence calculations proved to develop muscle memory on cranking and understanding disk access times. The calculation involves computing rotational delay, seek delay, and data transfer delay using given parameters such as RPM, transfer rate, and read size. These exercises reinforce how physical disk characteristics affect overall performance, and how to estimate the latency of accessing files on spinning disks. We also worked with inode-based file systems. Given inode sizes, inode numbers, and starting locations, we calculated exact inode addresses, identified their containing blocks, computed their offset within those blocks, and determined their index. This helped further solidify my understanding of how a file system maps logical structures (like inode numbers) to physical disk addresses. Additionally, we examined hierarchical file access and directory traversal. I learned how to compute the number of disk I/Os needed to resolve a file path like /foo/bar.txt, step-by-step through directory inodes and data blocks. We also looked at changes in file system state over time by analyzing transitions between inode bitmaps, data bitmaps, and directory structures. This involved understanding the effects of system calls like open(), creat(), write(), unlink(), and link() on both memory and disk structures. Each command changes the allocation and referencing of inodes and data blocks, revealing how file and directory operations impact the underlying metadata and block usage. We also covered the benefits of device drivers protecting the OS from device-related crashes. All in all, this week deepened both my practical and theoretical understanding of file system structures, access to paths/directories, and persistent storage.