Traditional file systems - performance problems


Indirections for large files => seeks

First fit allocation => fragmentation  => more seeks

Example: The disk in my laptop

File system sequential I/O: 16 Mb/s

Random I/O: 400 Kb.

Random I/O is in this case 40 times slower

Raw sequential I/O: 18 Mb/s

THE BIG ENEMY OF DISK PERFORMANCE: SEEKS!


Slide 11