AFS - Andrew File System (Distributed File System)

Several ideas

• it has local disk

• it cache whole file

• it flush upon close

1. read/write on local side

2. open/close -> send server data

• Update Visibility

  Solution: 1. flush on close 2. last writer wins

• Stale Cache

  Solution: tell client when the data is overwritten. ask callback when client cache data. no longer stateless.

Version 2

client cache entries and inodes for file

• Example

Error Handling

• Client crash

1. evict everything

2. recheck before using

• Low server memory

  tell clients and client mark the file as recheck

• Server crash

1. tell clients to recheck

2. persist callbacks

AFS vs NFS