Question

How would you design a system to update complex data structures on disk in a consistent fashion despite machine crashes?

Answer 1

To design a system to update complex data structures on disk in a consistent fashion despite machine crashes, the main objective is to go through the crash consistency problem. Due to power losses and crashes, the persistent data structure update is quite complex and this issue can lead to the crash-consistency problem.

Journaling is the solution to this problem. It reduces recovery time in such a way that the time reduces from O(disk volume size) to O(log size). This time reduction speeds up the recovery process after the crash.

Hope this helps.