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Some old articles: AIX Web-based System Manager

Mon, 10 Jun 2013 23:38:03 +0100

http://www.ibm.com/developerworks/cn/aix/library/0911_wangfeng_wsm1/
http://www.ibm.com/developerworks/cn/aix/library/0911_wangfeng_wsm2/
http://www.ibm.com/developerworks/cn/aix/library/0911_wangfeng_wsm3/

gzip, bzip and zip on Linux

Thu, 03 Jan 2013 02:21:52 +0100

In Linux, however, gzip is the predominant compression program with bzip2 being a close second. Linux users mainly use zip for exchanging files with Windows systems, rather than performing compression and archiving.

Freedom of Linux

Fri, 07 Dec 2012 01:50:54 +0100

Freedom is the power to decide what your computer does, and the only way to have this freedom is to know what your computer is doing. Freedom is a computer that is without secrets, one where everything can be known if you care enough to find out.

what is shell

Fri, 07 Dec 2012 01:16:15 +0100

The shell is simply a program that reads in the commands you type and converts them into a form more readily understood by the Unix system. It also includes some fundamental programming constructs that let you make decisions, loop, and store values in variables.

32-bit or 64-bit Linux?

Fri, 07 Dec 2012 01:16:50 +0100

The following information might help you decide whether to install 32-bit or 64-bit Linux on a 64-bit-capable processor.

• EM64T/AMD64 processors can run either version of Linux equally well.

• A 64-bit distribution allows each process to address more than 4 gigabytes of RAM.Larger address space is the biggest advantage of a 64-bit distribution. It is typically useful only for certain engineering/scientific computational work and when you are running multiple virtual machines.

• A 64-bit processor is not faster than a 32-bit processor in general; most benchmarks show more or less similar performance. In some cases the performance is better and in some cases it is worse: There is no clear performance advantage for either type of processor.

• The memory model for 64-bit Linux makes pointers twice as big as those in 32-bit Linux. This size difference translates to a more than 5 percent RAM usage increase, depending on the application. If a system is low on RAM, this overhead might make performance worse.

• ASLR (Address Space Layout Randomization) works better with the larger address space provided by 64-bit Linux. ALSR can help improve system security. See en.wikipedia.org/wiki/Address_space_layout_randomization.

• Some multimedia encoders run 10–30 percent faster under 64-bit Linux.

• Because more people are using 32-bit Linux, bugs in 32-bit Linux tend to be discovered and fixed faster than those in 64-bit Linux.

• Linux can set up Flashplayer and Java with a single click on 64-bit systems just as it can on 32-bit systems. However, for some applications, such as Skype, you must apply ugly workarounds to run them on 64-bit systems.

• Some features of proprietary third-party applications are not available for 64-bit architecture.

• There is no simple way to go back and forth between 32-bit and 64-bit versions of Linux without reinstalling Linux.

• If you are not sure which distribution to use, install the 32-bit version of Linux.

Linux Operating system basic

Fri, 07 Dec 2012 01:17:37 +0100

An operating system is the low-level software that schedules tasks, allocates storage, and handles the interfaces to peripheral hardware, such as printers, disk drives, the screen, keyboard, and mouse. An operating system has two main parts: the kernel and the system programs. The kernel allocates machine resources—including memory, disk space, and CPU cycles—to all other programs that run on the computer. The system programs include device drivers, libraries, utility programs, shells (command interpreters), configuration scripts and files, application programs, servers, and documentation. They perform higher-level housekeeping tasks, often acting as servers in a client/server relationship. Many of the libraries, servers, and utility programs were written by the GNU Project.