MBR partitioning rules are complex and poorly specified. Because this partition information is stored on the drive itself, the operating system is not dependent on the alignment. Starting with Windows Vista and Windows Server 2008, more logical boundaries are selected when the hardware provides better hints at the true cache or physical alignment. Windows creates MBR disk partitions and logical drives on cylinder boundaries based on the reported geometry, although this information no longer has any relationship to the physical characteristics of the hardware (disk driver or RAID controller). Extended partitions can then be subdivided into one or more logical disks. For more than four partitions, a secondary structure known as an extended partition is necessary. MBR disks support only four partition table entries. A new partitioning method was needed so the GUID Partition Table (GPT) partitioning scheme was created. Also, the layout, or format, of the MBR was designed for early computers and not flexible enough to accommodate newer disk configurations. The MBR information is also used by the operating system as a map of the volumes present on the disk.Įventually, data density for disks became too large for the MBR scheme to account for all the available data locations.

The MBR itself occupies a small amount of the disk and is read during the boot phase to determine where to locate the operating system to boot into. The MBR is a table of disk locations, or addresses, along with a certain length, of each of the partitions present on the disk. The partitions were organized using a scheme called the Master Boot Record (MBR). These sectors are grouped into partitions creating separate volumes, or 'drives' on a disk. Since the introduction of the personal computer, the data storage area on a hard disk has been divided into smaller areas called sectors. For a previous version of this FAQ, see Windows and GPT FAQ on MSDN. This version of the Windows and GPT FAQ applies to Windows 10 and Windows Server 2016. Answers to frequently asked questions about the GUID Partition Table (GPT).

Gpt iso