File systems facts

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Partition

A partition is a logical division of a storage device associated with a hard disk drive. Multiple partitions can be assigned to a single device in which case a drive letter is assigned to represent each partition. Multiple letters do not always mean that there are multiple devices, just multiple partitions. Some reasons why you may consider partitioning you hard drives are:

Assigning the boot system to a different partition than application and data files can help many computers run more smoothly and minimize damage in a system crash

It is sometimes necessary or useful for the swap file to be stored on its own partition.

Some operating systems cant run on a lard partition. Creating a separate partition for tour operating system can help it run properly

Assigning log files to be stored on distinct partitions can help minimize the effects of a system crash due to excessively large log files

Distinct operating systems can be assigned to run on assigned partitions to allow a dual boot system setup

Unallocated space is space on a partition that has not been assigned to a volume. You cannot store or read data in unallocated space

Volume

A volume is a single accessible storage area within a file system. A volume can encompass a single partition or span across multiple partitions depending on how it is configured and what operating system you are using. Volumes are identified by drive letters.

Directory

A directory (also called a folder) is a container in a volume that holds files or other directories. IT is used to logically sort and organize data to keep related files grouped together. Most operating systems use a hierarchal filing structure

File

A file is a one-dimensional stream of bits treated as a logical unit. They are the most basic component that a file system uses to organize raw bits of data on the storage device itself. The file name is made up if the directory h plus the file name. An extension can also be added to the filename to identify the file type and the program used to create, view, and modify the file.

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Basic

Basic disks use primary and extended partitions

Each physical disk can have up to four primary partitions or three primary partitions and one extended partition

Logical drives are defined within an extended partition. You can have up to 24 logical partitions on an extended. The extended partition can be divided into multiple logical drives

You must create a logical drive in an extended partition before you can format and store data (the logical drive, not the partition is the storage unit)

Basic disks are supported by all operating systems

A basic disk only supports volumes made up of contiguous disk space

Basic disks store partition information in a portion of the master boot record (MBR known as the partition table

The Partition table has room for up to our partition entries (hence the limitation on the number of primary partitions)

When an extended partition is used, one of the four entries points to an extended boot record (EBR). The EBR is located within the extended partition and contains information about the logical drives within the extended partition

Dynamic

Volumes on dynamic disks are like partitions and logical drives on basic disks.

Dynamic disks support up to 128 volumes

Dynamic disks support volumes that use discontiguous disk space

simple volumes contain disk space from a single hard disk (either contiguous or discontiguous space)

Spanned volumes contain disk space from multiple hard disks, grouped together into a single logical volume

Dynamic disks store partitioning information in a hidden database on all dynamic disks in the system