Back
Close

Linux Filesystems 101 - Block Devices

player_one
9,181 views
Previous: Welcome Next: Using the VM

What is a block device?

A block device is (in very general terms) a piece of hardware that provides data access in blocks (contiguous groups of bytes) as opposed to character devices which provides access to individual data bytes. In actual practice, the term "block device" typically is used to describe a device that provides persistent data storage such as a traditional hard drive, or an SSD, or more recently eNVM. Optical drives also fall under this designation, as do USB drives and tape drives.

Characteristics of a block device

Block devices of varying types tend to have a lot in common, which allows them to be treated categorically the same at a certain level of abstraction.

  • Data is typically buffered / cached on reads and (if applicable) writes
  • Data is typically organized into files, which are organized into a hierarchical directory structure
  • There are frequently some redundancy and / or failsafe measures implemented to recover from incomplete or otherwise damaged data
  • Access to data on a block device is almost always orders of magnitude slower than access to data in RAM
Create your playground on Tech.io
This playground was created on Tech.io, our hands-on, knowledge-sharing platform for developers.
Go to tech.io
codingame x discord
Join the CodinGame community on Discord to chat about puzzle contributions, challenges, streams, blog articles - all that good stuff!
JOIN US ON DISCORD
Online Participants