CS Online Learning Journal

  Week 8 – CST– 334 Operating System Module 8- Persistence Persistence, as it applies to Operating Systems, is the ability of data to be stored even after the systems crashes, is restarted, or power is turned off. Regular system memory like RAM is volatile and data saved on it is lost when the process is terminated. That is why the OS uses file systems to manage storage on external devices. The most common hardware used to store files has been the disk drive. When you create a file, work on it, and then save it to a disk drive, this file will remain saved in the disk drive even after you restart your computer or shut it down. Persistence, as it applies to a CST-334 online student, is the student’s ability to remain focused on the goal regardless of the difficulties or setback they may face. If the student unfortunately gets a low grade on an exam or assignment, their persistence will force them to dedicate more hours and find better ways to absorb material to improve their grade

Week 7 – CST– 334 Operating System Module 7- Persistence This week we covered persistence. We first learned about I/O devices and how the operating system interacts with these devices. In a typical system, the CPU is attached to the main memory via a memory bus. Devices like the PCI or graphics card are then connected to the system via a general I/O bus. Lastly, the peripheral buses like SCSI, SATA, or USB connect slow devices to the system like disks, mice, and keyboards. Modern systems have an I/O chip that connects directly to the CPU and to the peripherals devices. The DMA or Direct Memory Access engine can transfer data back and forth between devices without CPU intervention. Device drivers are software that the OS uses to know how a device works. An interesting fact is that the Linux kernel OS has 70% of its code in device drivers. We also studied Hard Disk Drives. These drives have been the main form of persistent data storage for many years and the file system is based on