Managing Disks
Types of Disk Partitions
Basic Disk Storage
- A basic disk is a hard disk initialized to use basic storage technology.
- A basic disk storage provides a simple means to logically organize disk space. A basic disk can have its space organized into one or more defined areas of storage called partitions. A partition is identified by its size and the type of data it is supposed to hold.
- A partition information is stored in the partition table of the MBR or GPT.
- Basic storage consists of
- a primary partition: It is a type of basic disk partition designed to store files that are used to load an operating system. A primary partition can be an active partition. An active partition is capable of starting an operating system. Each disk can have one active primary partition.
A basic disk usually contains only one primary partition, but it could have more. A single MBR-style basic disk can contain a maximum of four primary partitions limited by the partition table design. Windows 7 will only allow the creation of three primary partitions with the graphical Disk Management tool in Computer Management.
The first partition that is created on a hard drive is called a primary partition and is usually represented as drive C. Primary partitions use all the space that is allocated to each partition and use a single drive letter to represent the partition. Each physical drive can be partitioned as follows:
- as a single partition
- as four primary partitions
- as three primary partitions and one extended partition
- an extended partition: It takes the place of one of the primary partitions that can be created on the basic disk and does not have a drive letter or specific folder path assigned to it.
A single MBR-based basic disk can contain no more than one extended partition. The extended partition, if used, takes the place of one of the primary partitions that can be created on the basic disk. This means that if a basic disk has an extended partition, then a maximum of three primary partitions can exist on the same disk. GPT-based disks do not use or support extended partitions.
With an extended partition, you can allocate the space however you like, and each suballocation of space (called a logical partition) is represented by a different drive letter. For example, a 500 GB extended partition could have a 250 GB D partition and a 250 GB E partition.At the highest level of disk organization, you have a physical hard drive. You cannot use space on the physical drive until you have logically partitioned the physical drive. A partition is a logical definition of hard drive space.
- a logical partition:It can only be created using the free space inside an extended partition. Windows 7 refers to logical partitions as logical drives in disk administration utilities. If an extended partition does not have any free space, a new logical drive cannot be created inside the extended partition. The free space inside the extended partition is the only limit to how many logical partitions can be created inside it. A logical partition can be formatted using a file system to store files. Drive letters can be assigned to logical partition file systems.
http://www.microsoft.com/windowsxp/using/setup/expert/tulloch_partition.mspx.