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Explain like I’m five: what is disk parity?

Let’s break this down with a simple analogy:

Imagine you and two friends are holding three pieces of paper. You each write down a number.

  • You write down the number 5.
  • Your first friend writes down the number 7.
  • To figure out what the second friend should write, you add your numbers together: 5 + 7 = 12.

Now, here’s where the magic (or parity) comes in: instead of writing 12, the second friend writes down -12. That -12 is like the parity.

If you ever forget your number (let’s say your piece of paper gets lost), your friends can help you remember it. They take their numbers, add them together, and the result is 5. That’s your number!

In RAID 5, the system does a similar thing but with data on drives. By using this method, if a drive fails, the system can figure out the missing data using the remaining drives. It’s like a safety net for your information!