DistOS 2023W 2023-02-06 - Revision history

Soma: /* Discussion questions */

2023-02-06T17:00:23Z

Discussion questions

← Older revision		Revision as of 17:00, 6 February 2023
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	* What is the role of UNIX in the design and implementation of Sprite and AFS?		* What is the role of UNIX in the design and implementation of Sprite and AFS?
	* What else came to mind when reading and discussing these papers?		* What else came to mind when reading and discussing these papers?
			* What affects scale in AFS? Sprite?
			* What sort of workloads are these systems designed for?

	==Notes==		==Notes==

Soma at 16:59, 6 February 2023

2023-02-06T16:59:03Z

← Older revision		Revision as of 16:59, 6 February 2023
Line 5:		Line 5:
	* What is the role of UNIX in the design and implementation of Sprite and AFS?		* What is the role of UNIX in the design and implementation of Sprite and AFS?
	* What else came to mind when reading and discussing these papers?		* What else came to mind when reading and discussing these papers?

			==Notes==

			<pre>
			Sprite and AFS
			--------------

			- Sprite is similar to LOCUS in high-level design
			- but Sprite has optimized for performance in various ways
			- when migrating processes, only copy pages that you need
			(if executable is already on other workstation in memory can just use those pages)
			- caching on both client and server
			- caching of files in memory (we have more RAM)
			- efficient distribution of filesystem namespace
			- still not running on many workstations (100 workstations, 6 servers)
			- note the tradeoff between RAM and disks
			- do as much with RAM as possible, just use disks for persistence
			(very much what we do today)
			- Sprite seems very familiar because its caching architecture is very much how we do things today


			AFS
			- Andrew is for Andrew Carnegie, this came out of CMU (Carnegie Mellon Univ)
			- AFS was trying for web scale before the web
			- global filesystem
			- every organization was a "cell" and AFS allowed for inter-cell communication
			- but authentication normally didn't work outside a cell so you
			mostly wouldn't see anything except public files
			- took security seriously, integrated with Kerberos for authentication
			- takes a very different approach to accessing files
			- workstation assumed to have a local disk
			- so on open, a file would be copied to the local disk
			- all work on the file would happen locally
			- on close, file would be copied back to the server
			- quirk of the AFS model - close could fail!
			- do you check close for failure normally?

			In AFS, the servers are very different from the clients
			- complex Vice and Venus setup, for managing data blocks and metadata separately
			- designed for large installations

			AFS workstations couldn't work disconnected, but later systems tried to fix this (Coda, which didn't get that widely used)
			</pre>

Soma: Created page with "==Discussion questions== * Discuss what you think was interesting about Sprite relative to past systems. What was new? What was old? * How does AFS compare to NFS, in terms of their design, implementation, and ambition? * What is the role of UNIX in the design and implementation of Sprite and AFS? * What else came to mind when reading and discussing these papers?"

2023-02-06T16:17:18Z

Created page with "==Discussion questions== * Discuss what you think was interesting about Sprite relative to past systems. What was new? What was old? * How does AFS compare to NFS, in terms of their design, implementation, and ambition? * What is the role of UNIX in the design and implementation of Sprite and AFS? * What else came to mind when reading and discussing these papers?"

New page

==Discussion questions==

* Discuss what you think was interesting about Sprite relative to past systems. What was new? What was old?
* How does AFS compare to NFS, in terms of their design, implementation, and ambition?
* What is the role of UNIX in the design and implementation of Sprite and AFS?
* What else came to mind when reading and discussing these papers?