CS533 Concepts of Operating Systems Class 18 File Systems

CS533 - Concepts of Operating Systems 2 Questions  Why does read-optimized block placement perform very poorly for a write-dominated workload?  How should free space be managed for a read- dominated workload?  How should free space be managed for a write- dominated workload?

CS533 - Concepts of Operating Systems 3 Questions  What impact will the current rapid increase in disk capacity and decrease in cost per Mbyte have? o What if disk space was free?  With intelligent disk controllers should the file system manage placement at all?  What issues should concern a file system designer, beyond performance?

CS533 - Concepts of Operating Systems 4 Questions  How do mirroring and RAID-5 increase the reliability of file data? o What kinds of failures can be tolerated? o Why might you choose mirroring over RAID-5? o Why might you choose RAID-5 over mirroring?  If a storage device migrates blocks dynamically between mirrored and RAID-5 storage, how can file system software keep track of where data is?  If the storage system is log-structured, does the file system above it need to be log-structured?

CS533 - Concepts of Operating Systems 5 Questions  Need file system software above HP AutoRAID concern itself with free-space management?  Would the system benefit from using a device interface at a higher level of abstraction? o Why not implement the file abstraction at the device level?

CS533 - Concepts of Operating Systems 6 What next?  Final will be a take home o Shouldn’t take more than a couple of hours