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.

Previous slide

Next slide

Back to first slide

View graphic version