Linux 101 : Fdisk, MBR and GPT partitions



Disks are divided into different parts called partitions.
The partitions help isolate the system files from the "users" files. We would have different partitions for the system files and for the "users" files to avoid the risk of the "users" data filling up the disk and interfering with the functioning of the operating system.


MBR (Master Boot Record):

It is the boot sector at the beginning of the storage device.
The partition table holds information about the disk partitions.

MBR layout:
  • Can manages up to 2TB of disk space,
  • It can have four primary, but we could create an extended partition that could contain an unlimited amount of logical partitions.
Below we can see all the different types of partitions inside a disk:


GPT (GUID partition table):

GPT is a new disk layout that is replacing the MBR partition scheme.
GPT is part of the UEFI which is a replacement of the BIOS.
UEFI is a piece of software that runs before the operating system. UFEI supports among other things larger disk sizes.

GPT
  • Does not have primary or extended partitions.
  • It supports up to128 partitions.
  • It supports disks up to 9.4 ZB (Zettabyte) in size
  • It is not supported by older operating systems.
  • We need to use updated partitioning utilities that support GPT (fdisk, parted).
Displaying the partition table:

To display the partition table of the disks on a machine, we use:


Using fdisk to create MBR partitions:



Using fdisk to create GPT partitions:



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