NFS, AFS, Sprite FS - Revision history

Ndickson: Finished posting notes on NFS/AFS/SpriteFS/DSM

2008-10-23T20:29:18Z

Finished posting notes on NFS/AFS/SpriteFS/DSM

← Older revision		Revision as of 20:29, 23 October 2008
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	# How suitable are these filesystems in modern small networks? Enterprise networks? Internet-scale applications? Why?		# How suitable are these filesystems in modern small networks? Enterprise networks? Internet-scale applications? Why?

	==Notes==		==Notes from this and the previous week==
			Two main things to consider about new ideas for systems:
			* mental models
			* controls

			Are these solving some problem better than existing things, and are they better enough to overcome the disadvantages?

	===Bell Labs===		===Bell Labs===
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	* move from centralized to distributed computing to make use of the individual machines		* move from centralized to distributed computing to make use of the individual machines
	* resource utilization / efficiency		* resource utilization / efficiency
	* '''with Plan 9, you ~~don’t~~ know when ~~you’re~~ using a network (network transparency), because everything is just a file'''		* '''with Plan 9, you don't know when you're using a network (network transparency), because everything is just a file'''
	** is the overhead consistent? not always: this means that one ~~can’t~~ predict how "file" accesses will perform in the field		** is the overhead consistent? not always: this means that one can't predict how "file" accesses will perform in the field
	** reliability of "file" access relies on reliability of network and remote machines		** reliability of "file" access relies on reliability of network and remote machines

			===DSM===
			* tried to turn everything into RAM
			* wanted to make programming easier by not having to deal with sending data
			* resource utilization / efficiency (while still being DSM, as much as those conflict)
			* focus on a class of problems (not as general)
			* an abstraction of system resources ("is it the right abstraction?")
			* '''with DSM, you don't know when you're using a network (network transparency), because everything is just memory'''
			** is the overhead consistent? no: this means that one can't predict how programs will perform in the field
			** reliability of programs relies on reliability of network and remote machines

			With hardware-based DSM: processor doesn’t know what pages do and don’t need to be secure. It's also not a portable system design.

Ndickson: Started posting notes on NFS/AFS/SpriteFS

2008-10-23T20:17:26Z

Started posting notes on NFS/AFS/SpriteFS

← Older revision		Revision as of 20:17, 23 October 2008
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	# What are their limitations?		# What are their limitations?
	# How suitable are these filesystems in modern small networks? Enterprise networks? Internet-scale applications? Why?		# How suitable are these filesystems in modern small networks? Enterprise networks? Internet-scale applications? Why?

			==Notes==

			===Bell Labs===
			* tried to turn everything into a file
			* wanted to make OS easier to use for programmers of their systems
			* "simple" common API/protocol for I/O & IPC resources; "radical network transparency"
			* focus on process communication
			* portability
			* code reuse (of their own code), but ignored legacy code problem
			* "laziness" & "generality"
			* move from centralized to distributed computing to make use of the individual machines
			* resource utilization / efficiency
			* '''with Plan 9, you don’t know when you’re using a network (network transparency), because everything is just a file'''
			** is the overhead consistent? not always: this means that one can’t predict how "file" accesses will perform in the field
			** reliability of "file" access relies on reliability of network and remote machines

Soma at 19:38, 7 September 2008

2008-09-07T19:38:08Z

New page

==Readings==

* [http://homeostasis.scs.carleton.ca/~soma/distos/fall2008/sandberg-nfs.pdf Russel Sandberg et al., "Design and Implementation of the Sun Network Filesystem" (1985)]<br />This is the original NFS paper.

* [http://homeostasis.scs.carleton.ca/~soma/distos/fall2008/howard-afs.pdf John H. Howard et al., "Scale and Performance in a Distributed File System" (1988)]<br />This paper describes AFS and compares it to NFS.

* [http://homeostasis.scs.carleton.ca/~soma/distos/fall2008/sprite-caching.pdf Nelson, Welch, & Ousterhout, "Caching in the Sprite Network File System" (1988)]<br />This paper compares Sprite to AFS and NFS.

==Questions==

# What were the key design goals of NFS, AFS, and Sprite's FS?
# How well did they achieve their goals?
# What are their limitations?
# How suitable are these filesystems in modern small networks? Enterprise networks? Internet-scale applications? Why?