15-02-2013, 10:28 AM
Types of Operating System
[attachment=50993]
Mainframe Systems: Batch OS
The OS
was always resident in memory
automatically transferred control from one job to another.
Batching:
Programmers submitted jobs in a job control languages (shell, awk, perl)
Operators batched together jobs with similar needs and ran them through the computer as a group.
Drawbacks:
fast CPU and slow I/O devices.
Mainframe Systems: Multiprogrammed OS
Multiprogrammed OS (vs. uniprogrammed OS)
Keeping many jobs in memory (see the next slide)
Switching to another job if the CPU is idle
As long as at least one job needs to execute, the CPU is never idle.
Multiprogrammed OS
Job scheduling for selecting a job to load into memory
CPU scheduling for selecting which job to run
Memory management
Protection.
Drawback: not interactive
DESKTOP SYSTEMS
Personal computers
computer system dedicated to a single user.
I/O devices – keyboards, mice, display screens, small printers.
Individuals have sole use of computer and do not need advanced CPU utilization of protection features.
User convenience and responsiveness not maximizing CPU and peripheral utilization
Can adopt some of the technology developed for larger operating system.
Not much of utilization
Protection, and so on
Many possible OSes: (Windows, MacOS, UNIX, Linux)
PARALLEL AND DISTRIBUTED SYSTEMS
Two types
Tightly coupled systems
Parallel systems or multiprocessor systems
Processors share memory and a clock; communication usually takes place through the shared memory.
Loosed coupled systems
Distributed systems and clustered systems
Each processor has its own local memory; processors communicate with one another through various communications lines, such as high-speed buses or telephone lines.
Parallel and distributed systems: Clustered systems
Clustering allows two or more systems to share storage.
Provides high reliability.
Asymmetric clustering: one server runs the application while other servers standby.
Symmetric clustering: all N hosts are running the application.
[attachment=50993]
Mainframe Systems: Batch OS
The OS
was always resident in memory
automatically transferred control from one job to another.
Batching:
Programmers submitted jobs in a job control languages (shell, awk, perl)
Operators batched together jobs with similar needs and ran them through the computer as a group.
Drawbacks:
fast CPU and slow I/O devices.
Mainframe Systems: Multiprogrammed OS
Multiprogrammed OS (vs. uniprogrammed OS)
Keeping many jobs in memory (see the next slide)
Switching to another job if the CPU is idle
As long as at least one job needs to execute, the CPU is never idle.
Multiprogrammed OS
Job scheduling for selecting a job to load into memory
CPU scheduling for selecting which job to run
Memory management
Protection.
Drawback: not interactive
DESKTOP SYSTEMS
Personal computers
computer system dedicated to a single user.
I/O devices – keyboards, mice, display screens, small printers.
Individuals have sole use of computer and do not need advanced CPU utilization of protection features.
User convenience and responsiveness not maximizing CPU and peripheral utilization
Can adopt some of the technology developed for larger operating system.
Not much of utilization
Protection, and so on
Many possible OSes: (Windows, MacOS, UNIX, Linux)
PARALLEL AND DISTRIBUTED SYSTEMS
Two types
Tightly coupled systems
Parallel systems or multiprocessor systems
Processors share memory and a clock; communication usually takes place through the shared memory.
Loosed coupled systems
Distributed systems and clustered systems
Each processor has its own local memory; processors communicate with one another through various communications lines, such as high-speed buses or telephone lines.
Parallel and distributed systems: Clustered systems
Clustering allows two or more systems to share storage.
Provides high reliability.
Asymmetric clustering: one server runs the application while other servers standby.
Symmetric clustering: all N hosts are running the application.