2. Introduction to Linux
What is Linux, and Who Created it?
GNU and the GPL
Unix/GNU, What is the Difference?
POSIX Compliance
Other POSIX Operating Systems
Uses of Linux
Advantages and Disadvantages
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3. What is Linux
Linux is a UNIX clone
It can run on 32 bit and 64 bit hardware
Linux is a true multitasking environment
Fully capable of taking advantage of multiple processors
Can address up to 64 GB of RAM
Partial POSIX Compliance
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4. History
The history of Linux began with Unix in 1969
› Unix was created at Bell Labs with the goals:
Simplicity
Recycleable code
Written in C as opposed to assembly
Development started in 1991
› Linus Torvalds wanted to create a free implementation of
UNIX
› By 1993 there were 12000 Linux users
› Today Linux rivals UNIX in stability and scalability
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5. The Linux Kernel
The Linux kernel is currently maintained by Linus Torvalds and
a few hundred other developers
Releases are numbered in a very ordered fashion.
› Major.minor.patchlevel
› Odd minor numbers are development kernels
› Thus
2.4.20 latest stable kernel
2.5.67 latest development kernel
Will become the 2.6 kernel
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6. Design
The Linux kernel has a monolithic design
The other approach is the microkernel design
Both have their upsides and downsides
› Monolithic kernels
Easier to build and design
Generally faster
More recompiles
Less object oriented
› Micro kernels
Considered safer
Easier to develop drivers for
Only recompile for upgrades
Generally slower
Much harder to build and design
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7. So Why Should I Use Linux?
As a server platform
› few other operating systems can match Linux in:
Performance
Price
Stability
For Developers
› Resources:
Linux has a tremendous number of tools available for developers. And
they are all free.
For the Desktop
› It's fun
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8. Advantages
Linux is free
› Can't say that enough
› It's great for poor college students
Learning Linux means learning UNIX, and UNIX is the largest
server platform in the world
Community
› The Linux community is very active and helpful
› This makes support very rapid
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9. But it's hard to learn
Linux is much harder than Windows
It's harder to use than Windows
It lacks all those great automated installation tools
You have to manually configure hardware
There is lots of hardware out there that just won't run in Linux
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10. Some Linux Basics
File System
› Linux is much more hierarcal than Windows
Everything starts at the root
/
Boot -- contains the kernel and system map
Bin -- contains the basic system binaries
Dev -- all the device entries
Etc -- can't think of any other place to put it
Home -- where all the users live
Lib -- system libraries
Mnt -- place to mount filesystems
Proc -- system information
Root -- the root user's home
Sbin -- system binaries
Usr -- where user accessible programs go
Var -- logs and such
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