OS Distributed File Systems

process migration

system migration

thread migration

data migration

Mail service

File transfer

Remote access

All of the mentioned

cache coherence scheme

computation migration

remote procedure call

message passing

anytime

when it receives a reply message from its parent process

when it receives a reply message from all other processes in the system

none of the mentioned

Reduced network traffic by retaining recently accessed disk blocks

Faster network access

Copies of data creates backup automatically

None of the mentioned

All operations associated are executed to completion or none are performed

One processor as coordinator which handles all requests

When responses are received from all processes, then the process can enter its Critical Section

Use communication links

Basic cost

Communication cost

Reliability

All of the mentioned

Users are aware of multiplicity of machines

They are transparent

They are simple to use

All of the mentioned

Multiaccess bus

Ring

Star

All of the mentioned

Physical

Data link

Network

Transport