Advanced Operating Systems   COMP9242 2002/S2

UNSW

Printer-Friendly Version Administration                - Notices - Course Intro - Consultations # On-line Survey (closed) - Survey Results   Work - Lectures - Milestone 0 - Project Admin - Project Spec - Project FAQ - Exam   Documentation - ASysT Lab - L4 source browser - Sulima ISA Simulator - R4x00 ISA Summary  - MIPS R4700 Reference - MIPS R4000 User Manual  - Network Driver - GT64111   Related Info - Aurema OS Prize - OS Hall of Fame   History - 2000 - 1999 - 1998   Staff - Gernot Heiser (LiC)

Limitations of Traditional File Systems Observations: Many write operations required for some function (file creation): 5 writes, 2 synchronous (inode (2), dir, dir's inode, data). Seeks are expensive: Average seek costs as much as 100's of kB of data transfer. Big caches eliminate most reads: Write costs become critical. How can we eliminate synchronous writes, and seeks on writes? Normal logging helps only partially.