Today i am going to share some information regarding the MBR(MASTER BOOT RECORD) AND GPT(GUID PARTITION TABLE).
How MBR-Based Disks Work:-
The MBR is stored at a consistent location on a physical disk, enabling the computer BIOS to reference it. During the startup process, the computer examines the MBR to determine which partition on the installed disks is marked as active. The active partition contains the operating system startup files.
• Four partitions on each disk: MBR-based disks are limited to four partitions. All of these can be primary partitions, or one can be an extended partition with logical volumes inside. You can configure the extended partition to contain multiple volumes.
• A 2 Terabyte (TB) maximum partition size: A partition cannot be larger than 2 TB.
• No redundancy provided: The MBR is a single point of failure, and if corrupted or damaged, it can render the operating system non-bootable.
What is a GPT Disk?
When you install a disk in a computer that is running Windows 7, you can choose to
select one of two partitioning schemes:
• Master Boot Record (MBR)-based partitioning scheme
• Globally unique identifier (GUID) partition table (GPT)-based partitioning scheme
The following are common reasons to partition a disk:
• Separate operating system files from data and user files
• Place applications and data files in the same location
• Put cache, log, and paging files in a location separate from other files
• Create multiboot setup environments
What is MBR ?
MBR:-It contains the partition table for the disk and a small amount of executable code called the Master Boot code.
1.MBR is created when the disk is partitioned.
2.Contains 4 partition enter table.
3.Is on the first sector of the hard disk.
4.limits the number & size of partitions.
The MBR is stored at a consistent location on a physical disk, enabling the computer BIOS to reference it. During the startup process, the computer examines the MBR to determine which partition on the installed disks is marked as active. The active partition contains the operating system startup files.
Features of MBR-Based Disks:-
• A 2 Terabyte (TB) maximum partition size: A partition cannot be larger than 2 TB.
• No redundancy provided: The MBR is a single point of failure, and if corrupted or damaged, it can render the operating system non-bootable.
The GUID Partition Table (GPT) was introduced as part of the Unified Extensible Firmware Interface (UEFI) initiative. GPT provides a more flexible mechanism for partitioning disks than the older Master Boot Record (MBR) partitioning scheme that was common to PCs.
A partition is a contiguous space of storage on a physical or logical disk that functions as if it were a physically separate disk. Partitions are visible to the system firmware and the installed operating systems. Access to a partition is controlled by the system firmware before the system boots the operating system, and then by the operating system after it is started.
GPT-based disks address the limitations of MBR-based disks. GPT disks support: * 128 partitions per disk: This is a vast improvement over MBR-based disks. * 18 Exabyte (EB) volume size: This is a theoretical maximum because hard disk hardware is not yet available that supports such vast volume sizes. * Redundancy: The GPT is duplicated and protected by Cyclic Redundancy Checks (CRC). You can implement GPT-based disks on Windows Server® 2008, Windows Vista, and Windows 7. You cannot use the GPT partition style on removable disks. |
