CST 334 - Week VII

 Flavio Cervantes

CST334-40_2253

August 9th, 2025

    This week in CST 334 I have learned about the implementation of file systems using technologies such as Very Simple File systems, these file systems are utilizing for managing file permissions, space utilization and management, methods of accessing files/data, metadata and how data is structured. I also learned about how data structures are organized on physical hard drives, it involves tracks, cylinders, actuators + arm, head and platter. The space in between the head and disk is 5000x tinier than a human hair, it needs this close proximity to be able to read data efficiently and accurately. I also learned how Drive performance involves 3 steps such as waiting for the sector to rotate underneath the head, this is known as rotational delay. Then it seeks by moving the head to the right track, lastly is transfers the data as needed. I also learned the formula for calculating avg. its rotation / min, so for example if a disk spiks at 7.2RPM, one sets up the formula the multiple that by min/60 sec. Once you get than answer you multiple it by 1000 ms / sec and that gives you final number of 8.3 MS/REV.  Read or write on the other hand is calculated: Total time = rotation delay + seek time + transfer time. Regarding I/O devices, I learned that any computer involves memory, CPU and specialized chip. The HW interface involves a set of registers, status register which read to see devices status, the command register writes to tell the device to do something and the data register passes data to/from a device. The CPU communicates with IOs by interrupting, direct memory access or polling.