SASW@MIT-MC.ARPA ("Steven A. Swernofsky") (12/07/85)
MSG: *MSG 4790
Date: 12/06/85 11:38:31
From: LYALL at MIT-XX.ARPA
Re: Seminar
Received: from MIT-XX.ARPA by MIT-MC.ARPA 6 Dec 85 11:38:18 EST
Date: Fri 6 Dec 85 11:34:59-EST
From: Neena Lyall <LYALL@MIT-XX.ARPA>
Subject: Seminar
To: *mac@MIT-MC.ARPA
cc: lyall@MIT-XX.ARPA
Message-ID: <12164973450.26.LYALL@MIT-XX.ARPA>
Wednesday, December 11, 1985
2:15 Refreshments
2:30 Lecture
Room: NE43-512A
A DISTRIBUTED FILE SYSTEM FOR A NETWORK OF WORKSTATIONS
Paul Leach and Nathaniel Mishkin
(Apollo Computer)
The Apollo workstation supports a distributed file system based on the concept
of a "single-level store." Files are "objects" identified by 64 bit IDs that
are unique across all Apollo file systems. A process accesses an object's data
by mapping the object into the process's address space and making normal memory
references. The distinction between local and remote objects is known only to
the pager, which loads objects' pages on demand.
We will discuss several aspects of this architecture that we feel are crucial
to its success: a distributed lock manager, caching of object data, a
network-wide registry of users, and a distributed, replicated naming database
that is used to locate nodes based on name.
Conventional stream I/O (open, close, read, write, etc.) is provided by
"Streams." Streams can be used to access objects in the single-level store and
other objects that support the concept of stream I/O (e.g. tape drives,
terminal) I/O lines. Streams is object-oriented and extensible---the behavior
of Streams depends on the type of the object. Users can define new types of
objects and write managers that implement the stream operations for the new
type.
We will discuss the the principles behind Streams' extensibility and describe
how we see it being used as the mechanism for supporting file system
connections in a heterogeneous environment.
The Apollo distributed file system has been implemented on a 680x0
microprocessor-based workstation. Workstations are connected by a 12MB token
ring; rings can be connected by gateways to form an internetwork. All
workstations in the internet have equal access to the distributed file system.
The internet at Apollo Computer has over 1000 workstations.
Host: Professor Richard E. ZippelSASW@MC.LCS.MIT.EDU ("Steven A. Swernofsky") (02/22/86)
Date: 20 Feb 1986 1204-EST
From: ALR at XX.LCS.MIT.EDU
Subject: SEMINAR
SEMINAR
DATE: MONDAY, FEBRUARY 24, 1986
TIME: REFRESHMENTS AT 3:00 PM
TALK AT 3:15 PM
PLACE: ROOM NE43-512A
THE ANDREW FILE SYSTEM: PRINCIPLES AND DESIGN
M. SATYANARAYANAN
Carnegie-Mellon University
ABSTRACT
Andrew is a computing and communication system consisting of
thousands of personal computer workstations linked by a
location-transparent distributed file system. The design of Andrew
is a synthesis of the best features of personal computing and
timesharing. It combines the rich user-machine interface and
predictable performance characteristic of personal computing with the
ease of information sharing typical of timesharing systems. This
system is being built at Carnegie-Mellon University in collaboration
with IBM.
In the talk, I will focus on the design and rationale of the
distributed file system for Andrew. While scale has been the
dominant design influence, careful attention has also been paid to
the goals of location transparency, user mobility and compatibility
with existing operating system interfaces. Security is an important
design consideration and the mechanisms for it do not assume that the
workstations or the network are secure. Caching of entire files at
workstations is a key element in this design.
In the latter part of the talk, I will discuss our usage experience
with an initial prototype and the conclusions which led to the
current implementation. A configuration of about 150 workstations is
in use by more than 500 users at the present time. These numbers are
expected to grow by an order of magnitude over the next two years.
HOST: PROF. LISKOV