What Are Basic Disks and Volumes?
Updated: March 28, 2003
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
In this section
Basic disks and basic volumes are the storage types most often used with Windows operating systems. The term basic disk refers to a disk that contains basic volumes, such as primary partitions and logical drives. The term basic volume refers to a partition on a basic disk. Basic disks, which are found in both x86-based and Itanium-based computers, provide a simple, elegant storage solution that can accommodate changing storage requirements. Basic disks support clustered disks, Institute of Electrical and Electronics Engineers (IEEE) 1394 disks, and universal serial bus (USB) removable drives.
In x86-based computers running Windows Server 2003, basic disks use the same Master Boot Record (MBR) partition style as the disks used by Microsoft MS-DOS, and all previous versions of Microsoft Windows.
Itanium-based computers also support basic disks, but you can choose from two partition styles (MBR or GPT) for each basic disk. You can create up to 128 volumes on an MBR or GPT disk. The partition style determines the operating systems that can access the disk.
Before you can create simple volumes, spanned volumes, or volumes that use redundant array of independent disks (RAID) technology (striped volumes, mirrored volumes, and RAID-5 volumes) you must convert a basic disk to a dynamic disk.
Windows Server 2003 supports the following types of basic volumes:
Primary partitions (master boot record (MBR) and GUID partition table (GPT) disks)
Logical drives within extended partitions (MBR disks only)
The number of basic volumes you can create on a basic disk depends on the partition style of the disk:
On MBR disks, you can create up to four primary partitions, or you can create up to three primary partitions and one extended partition. Within the extended partition, you can create up to 128 logical drives.
On GPT disks, you can create up to 128 partitions. Because GPT disks do not limit you to four partitions, extended partitions and logical drives are not available on GPT disks.
If you want to add more space to existing primary partitions and logical drives, you can extend the volume using the extend command in DiskPart.
Basic Disk and Volume Scenarios
Basic disks and volumes can be scaled to match your storage needs. Basic disks and volumes are commonly used in the following scenarios.
Home or business desktop computer with one disk
Most home and business users require a basic disk and one basic volume for storage, and do not require a computer with volumes that span multiple disks or that provide fault-tolerance. This is the best choice for those who require simplicity and ease of use.
Home or business desktop computer with one disk and more than one volume
If a home or small business user wants to upgrade the operating system without losing their personal data, they should store the operating system in a separate location from their personal data. In this scenario, a basic disk with two or more basic volumes is required. The user can install the operating system on the first volume, creating a boot volume or system volume, and use the second volume to store data. When a new version of the operating system is released, the user can reformat the boot or system volume and install the new operating system. Their personal data, located on the second volume, remains untouched.
Business server with one disk and multiple volumes and logical drives
If a small business operates a file server and requires multiple volumes for file sharing and file security, the system administrator can create up to three primary partitions and one extended partition with up to 128 logical drives. In this scenario, each of the partitions and logical drives receives its own drive letter so that each of these volumes can be individually secured to limit access to specific, authorized users.
For example, perhaps each department within this business requires its own volume. The business could create individual volumes and grant permissions to members of those departments. Data shared by members of human resources, for example, could be kept separate from the data used by members of the accounting, sales, or marketing departments.
As storage needs and the importance of the data stored on disk increase, the logical next step for this business would be to add additional disks to the server, convert the disks to dynamic, and then create fault-tolerant mirrored- or RAID-5 volumes.