文章目录[隐藏]
Credit
self learnt from https://www.csie.nuk.edu.tw/~wuch/course/csd511/csd511-08.pdf
Intro
After viewing much of the ppt online, I grabbed that most of the US schools focus on practice. Maybe because the ppt is for Microsoft intern. Actually, the Sun and the Andrew has been the history.
First off, many kinds. and all of them is to make online repositories browsed just as offline. like ftp on linux r samba on windows.
basic Architechture
The architecture is the webserver one that is response and response. I'd say it's more r less a application layer thing, all the mapping connects to other api. In ufid part, it's stateless and a server end fd.
Implementation
The connection contract is based on RPC which requires:
This is the remote procedure call interface to extend the local directory services to a distributed model.
Every operations would not be directly modified, all requires a tcp requiest, so the identifier requires a 32bits and 16bits date for time stamp. After being transfered, all operations are similar to local ones. Take Sun NFS systems as instance.
NFS & VFS
VFS do it more direct, I would say. It put the Hardware abstraction more abstract based on network architechture. Vnode rather than Inode( a file saving DS). In pintos is like:
while VFS works this way
Summary
Other OS operations works just do as the file system based on network.
optimization: UDP packet is extended to 9KB to containing entire file block (8KB for UNIX BSD FFS) and RPC message in a single packet – Clients and servers of NFSv3 can negotiate sizes larger than 8 KB.
Another file systrm : Andrew File System
The Andrew File System (AFS)[1] is a distributed file system which uses a set of trusted servers to present a homogeneous, location-transparent file name space to all the client workstations. It was developed by Carnegie Mellon University as part of the Andrew Project.
Goal: provide transparent access to remote shared files
Two unusual design characteristics
Other improvement
further study
