Logical Disks

Basic Disks

A basic disk under Windows Server is essentially the same as the disks used under earlier versions of Windows, ie: a physical disk with primary and extended partitions.

If you choose to format your basic disk to the File Allocation Table (FAT or FAT32) file system, it has the following characteristics:

  • You can create up to three primary partitions and one extended partition on a basic disk or four primary partitions.
  • You can create a single extended partition with logical drives on a basic disk.
  • You can also extend a basic partition, but only by using the diskpart.exe command-line tool, which we’ll look at later.

When you install a Windows server operating system, the system automatically configures the existing hard disks as basic disks, unless they are already configured as dynamic from a previous installation.  Basic disks store their configuration information in the Partition Table, which is stored on the first sector of each hard disk. Under Windows 2000 and later operating systems, basic disks can store only partitions while dynamic disks can store only volumes.

Mirrored and RAID-5 volumes are fault-tolerant volumes that are available under the from Windows 2000 Server onwards.

Fault-tolerant volumes are designed to withstand a single disk failure within a set of disks and to continue functioning until the failed disk is replaced.

mirror set (called a mirrored volume in Windows Server) duplicates data to a second physical disk.

A stripe set with parity (called a RAID-5 volume in Windows Server) writes data across several disks (between 3 and 32 physical disks) and stores parity information across all the drives to be able to retrieve data in the event of a single failed disk. RAID-5 volumes cannot recover data if more than one drive in the set fails at the same time.

Next: Dynamic Disks