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MBR (an acronym for “Master Boot Record”) is the first sector on a hard disk, which starts the process of booting the computer. The MBR contains the partition table for the disk and a small amount of executable code called the master boot code. The MBR is a very important data of the hard disk. Damaging the MBR may result in the loss of all partitions of the hard drive.

The MBR has the following disadvantages:

  • Supports up to 4 primary partitions, or 3 primary partitions + an extended one
  • Supports volumes up to 2 TB (terabytes)
  • Uses hidden sectors to store system information
  • Replication and CRC are NOT features of MBR's partition table
  • Arbitrary number of logical partitions within the extended partition
  • The logical partition meta-data is stored in a linked-list structure
  • One byte partition type codes which leads to many collisions