Shared File Directory : Hugh's Lab
File system : pull
A directory containing files that hold shared state
Absolute Consistency ! : Only one host can write data to the same file at
a time.
Locate the file containing information and read/write the file data (file:user,
object information)
Read and the reopen in write only mode
Maintain "lock" information for each file, and only one writer may
hold that lock at a time
Ex. : NFS, AFS
Pros.
-
Simplest to program
-
Highest consistency
Cons.
-
Slow data update and access
-
Does not support many users
Constant need to open, update, close remote
file