Disk Partition
| Depends on | Filing System Implementation • Security • Disks |
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What is called “a disk” might, physically, be more than one physical disk – and may be more than one device (such as RAID); all the physical details can be hidden by abstraction.
Similarly a ‘single’ disk may be logically divided into partitions.
A partition is a virtual disk which is mapped onto a physical one. These may still be combined within the same file system, but for most intents and purposes, each partition is essentially its own device - moving files from one partition to another always requires re-writing all the data in the file, and a partition may be completely destroyed without affecting any data in a different partition.
A partition must be "mounted" in order to be made available to most programs, akin to mounting a physical drive on a rack. Different partitions need to be mounted separately, while a single partition is always mounted in its entirety.
Different partitions may serve different purposes. For example one partition could be file store whilst another is used for page swapping, which used to be the default configuration for Linux distributions like Ubuntu.
Different algorithms and permissions could be applied to different partitions. For instance, a data partition - where one might store their casual photos and documents - may use the FAT32 file system, which does not support permissions, while a Linux OS installation might be on an ext4 file system, which supports rwx permission bits and user/group ownership of files.
| Also refer to: | Operating System Concepts, 10th Edition: Chapter 15.3, pages 601-602 |
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