Disk Partition: Difference between revisions

From COMP15212 Wiki
gravatar Yuron [userbureaucratinterface-adminsysopPHRhYmxlIGNsYXNzPSJ0d3BvcHVwIj48dHI+PHRkIGNsYXNzPSJ0d3BvcHVwLWVudHJ5dGl0bGUiPkdyb3Vwczo8L3RkPjx0ZD51c2VyPGJyIC8+YnVyZWF1Y3JhdDxiciAvPmludGVyZmFjZS1hZG1pbjxiciAvPnN5c29wPGJyIC8+PC90ZD48L3RyPjwvdGFibGU+] (talk | contribs)
m (1 revision imported)
gravatar W81054ch [userbureaucratinterface-adminsysopPHRhYmxlIGNsYXNzPSJ0d3BvcHVwIj48dHI+PHRkIGNsYXNzPSJ0d3BvcHVwLWVudHJ5dGl0bGUiPkdyb3Vwczo8L3RkPjx0ZD51c2VyPGJyIC8+YnVyZWF1Y3JhdDxiciAvPmludGVyZmFjZS1hZG1pbjxiciAvPnN5c29wPGJyIC8+PC90ZD48L3RyPjwvdGFibGU+] (talk | contribs)
m (1 revision imported)
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
{{#set: Priority=1 | Summary=A logical (rather than physical) division of some backing store.}}<!--
{{#set: Priority=1 | Summary=A logical (rather than physical) division of some backing store.}}<!--
-->{{#invoke:Dependencies|add|Filing System Implementation,3|Security,2|Disks,3}}
-->{{#invoke:Dependencies|add|Filing System Implementation,3|Security,2|Disks,3}}
What is called “a disk” might, physically, be more than
What is called “a disk” might, physically, be more than one physical disk – and may be more than one device (such as [https://en.wikipedia.org/wiki/RAID RAID]); all the physical details can be hidden by abstraction.
one disk – and may be more than one device (such as
[https://en.wikipedia.org/wiki/RAID RAID]); we don’t really care,
here.


Similarly a ‘single’ disk may be <em>logically</em> divided into
Similarly a ‘single’ disk may be <em>logically</em> divided into [https://en.wikipedia.org/wiki/Disk_partitioning partitions].
[https://en.wikipedia.org/wiki/Disk_partitioning partitions].


A partition is a <em>virtual</em> disk which is mapped onto a physical one.
A partition is a <em>virtual</em> disk which is mapped onto a physical one. These may still be combined within the same [[Filing_System | 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.
These may still be combined within the same [[Filing_System | file
system]].


Different partitions may serve different purposes.  For example one
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.
partition could be file store whilst another is used for [[Paging | page
 
swapping]].
Different partitions may serve different purposes.  For example one partition could be file store whilst another is used for [[Paging | page swapping]], which used to be the default configuration for Linux distributions like Ubuntu.
Different algorithms and permissions could be applied to different
 
partitions.
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 [[FAT]]32 file system, which does not support permissions, while a Linux OS installation might be on an [[Journalling File System|ext4]] file system, which supports rwx permission bits and user/group ownership of files.
----
----
{{BookChapter|15.3|601-602}}
{{PageGraph}}
{{PageGraph}}
{{Category|Security}}
{{Category|Security}}
{{Category|User}}
{{Category|User}}

Latest revision as of 10:02, 5 August 2019

Depends on Filing System ImplementationSecurityDisks

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


Articles on User
"Everything is a File" • Application Binary Interface (ABI) • Arrays • Boot • Buffer Overflow • Containers • Daemons • Disk Partition • Dynamic Memory Allocation • Emulator traps • Environment Variables • Errors • Exceptions • File Attributes • File Locking • File Permissions • Introduction to Operating Systems • Journalling File System • Links • Locks • Man(ual pages in Unix) • Memory Mapped Files • Monitoring • Network File System (NFS) • PATH • Pipes • Pointers • Relocatable Code • Reset • SETUID • Shell • Sockets • Spooling and Buffering • Streams • Structures • Superuser • System Calls • Unix Signals • User • Using Peripherals