What are disks?

A disk is a mass storage block_device which we can write to and read from.

SCSI

  • Small Computer System Interface, responsible for handling disk access on most Linux systems.
  • It is a protocol that allows communicaton between printers, scanners and other peripherals in addition to harddisks.

Disk schematic

The following diagram represents the basic anatomy of a disk device.

  • A disk is divided up into Partitions which are subsections of the overall disk. The kernel presents each partition as a block device as it would with an entire disk.
  • The disk dedicates a small part of its contents to a partition table: this defines the different partitions that comprise the total disk space.
  • The filesystem is a database of files and directories: this comprises the bulk of the partition and is what you interact with in user space when reading and writing data.
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