LogFS

We are currently in the middle of a storage shift --from rotating magnetic disks to silicon-based flash media. With the change of media, there comes a change of accompanying problems. Rotational latency is replaced with large blocks and wearout. The change in media allows for two design principles.

Either leave the storage system from the device drivers up unchanged and fashion solid state "disks" that behave largely like traditional hard drives, hiding any differences in device firmware. Several device manufacturers have picked this approach, and for good reasons. It provides a market differentiator and an argument for higher prices.

Alternatively one can leave the flash largely as-is and change the storage system to match the new devices. LogFS is one example for this approach, providing a filesystem designed for raw flash and commodity devices alike. This presentation will give an introduction of LogFS. It will explain limitations in flash devices, show how to achieve decent performance with such limitations and --hopefully-- provide some enternainment for the crowd.