Persistence
Explore how operating systems ensure data persistence through hardware and software components like file systems and storage devices. Understand the role of system calls in file creation, writing, and closing. Discover how file systems manage storage efficiently and maintain reliability through techniques such as journaling and copy-on-write to handle crashes and failures.
We'll cover the following...
The third major theme of the course is persistence. In system memory, data can be easily lost, as devices such as DRAM store values in a volatile manner; when the power goes away or the system crashes, any data in memory is lost. Thus, we need hardware and software to be able to store data persistently; such storage is thus critical to any system as users care a great deal about their data.
The hardware comes in the form of some kind of input/output or I/O device; in modern systems, a hard drive is a common repository for long-lived information, although solid-state drives (SSDs) are making headway in this arena as well.
The software in the operating system that usually manages the disk is called the file system; it is thus responsible for storing any files the user creates in a reliable and efficient manner ...