Post on 27-Mar-2015
Advanced Operating Advanced Operating SystemsSystems
Prof. Muhammad Saeed
Distributed Operating Systems Distributed Operating Systems
Advanced Operating Systems 2
DefinitionDefinition
Advanced Operating Systems 3
Advantages (1)Advantages (1)
Advanced Operating Systems 4
Advantages (2)Advantages (2)
Advanced Operating Systems 5
DisadvantagesDisadvantages
Hardware ConceptsHardware ConceptsSISD:
SIMD:
MISD & MIMD:
Advanced Operating Systems 7
Hardware Concepts (1)Hardware Concepts (1)
Bus-Based Multiprocessors
Cache: 1) Write through 2) Snoopy
Advanced Operating Systems 8
Hardware Concepts (2)Hardware Concepts (2)
Switched Multiprocessors
nlog(n)/2
Advanced Operating Systems 9
Hardware Concepts (3)Hardware Concepts (3)
Bus-Based Multicomputers
Advanced Operating Systems 10
Switched Multicomputers
a) Grid b) Hypercube
Hardware Concepts (4)Hardware Concepts (4)
Advanced Operating Systems 11
Hardware ConceptsHardware Concepts
One feature that is commonly characterizing tightly coupled systems is that they share the clock.Therefore multiprocessors are typically tightly coupled but distributed workstations on a network are not.Another difference is that: in a tightly-coupled system, the delay experienced when a message is sent from one computer to another is short, and data rate is high; that is, the number of bits per second that can be transferred is large. In a loosely-coupled system, the opposite is true: the intermachine message delay is large and the data rate is low. For example, two CPU chips on the same printed circuit board and connected by wires etched onto the board are likely to be tightly coupled, whereas two computers connected by a 2400 bit/sec modem over the telephone system are certain to be loosely coupled.
Loosely-coupled & Tightly-coupled
Advanced Operating Systems 12
Software ConceptsSoftware Concepts
Multiprocessing Timesharing System
Advanced Operating Systems 13
Software ConceptsSoftware Concepts
Advanced Operating Systems 14
Design IssuesDesign Issues
1)Transparency2)Flexibility3)Reliability4)Performance5)Scalability
Advanced Operating Systems 15
Software ConceptsSoftware Concepts
Advanced Operating Systems 16
Advanced Operating Systems 17
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Courtesy of University of PITTSBURGH