Linux

1
Linux

• Collin Power
• Grant Strong
• Mike Lee
• Krista Fowler

2
Background
3
Release Dates

• First version developed Finnish university
  student Linus Torvalds as a hobby and released on
  October 5, 1991
• Linux Kernel 1.0 released in 1994
• Latest version (2.6.18) released on September 20,
  2006
• Thousands of distributions being released today
• Combinations of Linux and GNU Free Software
  Project and other developers libraries and tools

4
System Requirements

• For home users an x86-based system
• 32bit or 64bit x86 processor (Intel and clones
  like Cyrix, AMD and TI)
• ISA, EISA,PCI or VLB Bus
• 4 MB or more RAM
• 1.44MB or 1.2MB floppy drive
• VGA compatible video card
• 40MB of hard disk space (after installing all
  modules)
• CD-ROM drive if installing from CD

5
Advantages and Disadvantages
6
Advantages

• Runs on a wide range of hardware
• Has necessary productivity tools
• Word Processors
• Internet Browsers
• Stability
• Security
• Free

7
Disadvantages

• Learning curve
• Equivalent programs
• User interface
• Lack of support

8
Usability
9
Popularity

• Being adopted worldwide as a server and client
  desktop platform
• IBM
• Sun Microsystems
• Hewlett-Packard
• Novell
• Average Consumers
• Use of Linux is growing in less developed
  countries
• Cost effective
• Compatibility, Reliability, and Open Source
  nature driving popularity

10
User Friendliness

• Linux is becoming more user friendly
• Online tutorials on install, configuration, and
  use
• Linux User Groups around to help with problems
• Friendliness depends on distribution of Linux

11
Linux Distributions

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(No Transcript)
13
Compatibility
14
Drivers

• Hardware compatibility depends on drivers
• Some hardware vendors provide drivers
• Creative
• nVidia
• ATI
• Users have to write other drivers
• Hard to find, compile, and install
• Could be stability issues
• Linux Distributions often handle driver headaches

15
Software

• Open Source
• Proprietary
• Windows
• Emulation
• WINE Project
• Games
• TransGaming Technologies
• Cedega

16
Portability

• Porting
• adapting software so that an executable can be
  created for a different computing environment
• One of the most widely ported operating system
  kernels
• HP iPAQ
• Handheld Computer
• Microsofts Xbox
• Gaming Console
• IBM System z9
• massive mainframe server that can run hundreds or
  even thousands of concurrent Linux instances

17
Stability
18
Example

• ZDnet
• 10-month test
• OpenLinux, Red Hat Linux, and Microsofts Windows
  NT Server 4.0 with Service Pack 3
• identical hardware and network requests sent in
  parallel for standard Internet, file, and print
  services
• Result
• NT crashed once every six weeks on average 30
  minute fixes
• Neither GNU/Linux server ever went down

19
Example

• IBM
• Extreme stress tests for 30 and 60 days on the
  Linux kernel and core OS components
• Zero critical system failures
• System performance was not degraded
• Scaled hardware resources (CPU, memory, disk) on
  Symmetric Multiprocessing (SMP) systems correctly
• Handled continuous full CPU load (over 99) and
  high memory stress well
• Conclusion
• the Linux kernel and other core OS components
  are reliable and stable ... and can provide a
  robust, enterprise-level environment for
  customers over long periods of time.

20
Failure Rates as Measured by Fuzz Tests

• Feeding programs random characters and
  determining which ones resisted crashing and
  freeze-ups

21
Extreme Uptime

• rs1.nsmb.com
• 1.3GHz Celeron, 1GB of RAM, 2.4 era Kernal
• Powers websites under NSMB.com including a very
  busy forum
• Pounded all day long, every day

22

• root_at_rs1 log w
• 227pm up 720 days, 1515, 2 users, load
  average 7.29, 4.92, 4.28
• root_at_rs1 log vmstat 2
• procs memory swap
  io system cpu
• r b w swpd free buff cache si so
  bi bo in cs us sy id
• 6 0 0 89464 9508 4112 338948 6 8
  0 8 2 2 8 10 9
• 6 0 0 89464 9508 4112 338948 0 0
  0 0 653 74 89 11 0
• 6 0 0 89464 9508 4112 339972 0 0
  510 0 774 183 81 19 0
• 6 0 0 89464 9516 4108 339980 0 0
  0 64 740 130 87 12 0
• root_at_rs1 log ps -ef grep httpd wc -l
• 122

23
Reasons

• X Window System runs in user space not kernel
  space
• Contrasts with Microsoft Windows
• Managed by the Linux Kernel as a process, not the
  integral to the OS
• X Window System may crash but processes remain
  active in the background
• Open Source community forms a meritocracy
• Skill level determines role in project (e.g.
  highly able and experienced individuals manage
  critical components)
• No deadlines
• Faulty products are not pushed to the public
  based on time restraints
• Lowest bug density in release versions
• "given enough eyeballs, all bugs are shallow (E.
  S. Raymond)
• Community responds to flaws

24

• Linux drivers get the same kind of scrutiny as OS
  components
• Third Party Driver problems cause reliability
  issues for Windows
• Modular Code
• Reliable and easier to change
• Push to make code maintainable for all future
  developers
• Device drivers are modules
• Loaded or unloaded while running the system
• Less rebooting on updates
• Conclusion
• Open Source Software can be of high quality

25
Issues

• Open Source
• Many hands making many changes
• Problems sometimes reintroduced in new releases
• Naming conflicts common
• E.g. ipchains/iptables/netfilter firewall name
• Documentation sometimes poor
• Focus is on development not on document

26
Sources

• Stability
• http//www.dwheeler.com/oss_fs_why.htmlreliabilit
  y
• http//www.vmunix.com/mark/blog/archives/2004/10/1
  3/linux-stability/
• http//www-128.ibm.com/developerworks/library/l-hw
  1/
• http//www-306.ibm.com/software/info/features/feb1
  52005/reliance
• Compatibility
• http//www.winehq.com/
• http//www.transgaming.com/
• http//www.linuxcompatible.org/compatibility.html
• http//www.ipaqlinux.com/
• http//www-03.ibm.com/servers/eserver/zseries/os/l
  inux/