AFS File Validation
Older AFS versions:
- On open: the Venus access the vice to see if its copy of the file is still valid. This causes a substantial delay even if the copy is valid.
- The Vice is stateless.
Newer AFS versions:
- The Vice maintains lists of valid copies. If a file is modified the Vice invalidates other copies.
- On open: if the Venus has a valid copy it can open it immediately.
- If Venus crashes it has to invalidate its version or check their validity.