Chapter 2 Linux Kernel and Distributions |
29 |
In this chapter, you will learn more about the Linux kernel, including information on how you can use kernel versions to determine the status, features, and reliability of the kernel. This chapter also includes a listing of Linux resources, and I dis-
cuss an easy way to use these resources. In fact, I show you how to use Linux resources in order to learn how to install, modify, and use packages and applications. Packages and applications are usually distributed as a vendor distribution, so I will discuss these distributions and also list some of the most popular ones. After this chapter, you should have a better understanding of these important Linux concepts, and you should be able to identify the kernel version, Linux resources, packages, applications, and distributions — and how they are used to create a software package that you may want to use.
Linux Kernel
The kernel is the core of the operating system and provides the ability for software to access the hardware systems. Because the Linux kernel is used to access hardware, the kernel is often updated. These updates to the kernel are used to provide or improve support for newer technologies, such as SCSI controllers, Ultra ATA, USB, IEEE-1394, video cards, and other devices that are not properly supported by the previous kernel. The Linux kernel uses modules to add support for new devices and improve support for existing devices.
The use of modules prevents the entire Linux kernel from requiring constant replacement because the administrator can simply update the module to improve or provide support for the desired device. Modules, however, have limits, and you may have many reasons to update and recompile the entire kernel — to achieve, for example, better stability, performance, and improved support for all hardware. Keeping track of kernel changes can be a challenge, but by using a simple numbering system, Linux users can identify their current kernel version.
Kernel versions
1.9 Identify how the Linux kernel version numbering works
The kernel versions are used to determine the status, feature set, and reliability of the kernel. This kernel version numbering system ensures the availability and easy identification of each kernel. This system is summarized in the following list (Table 2-1 lists major kernel versions, including basic information about each version):
Major number: This is the leftmost number, and it reflects a major change in the kernel.
Minor number: This is the middle number and reflects the stability of a particular kernel. Even numbers indicate a stable release, and odd numbers indicate a developmental release.
30 Part I Linux Basics
Revision number: This is the last number and indicates the version of the overall release. For example, 2.4.4 is the fourth subversion of the 2.4.0 kernel.
Linux kernel version numbering is used often and is an important subject. You don’t have to memorize every detail about each Linux kernel, but you should understand the revision numbers and the purpose of updating the kernel.
Table 2-1
Linux Kernel Versions
Kernel |
Date |
Size |
Status |
Subversions |
||
|
|
|
|
|
|
|
0.01 |
17 |
September 1991 |
63,263 |
Stable |
2 |
|
|
|
|
|
|
|
|
0.10 |
3 |
December 1991 |
90,032 |
Stable |
2 |
|
|
|
|
|
|
|
|
0.95 |
8 |
March 1992 |
116,059 |
Developmental |
4 |
|
|
|
|
|
|
|
|
Pre-0.96 |
22 |
April 1992 |
131,606 |
Pre-Release |
0 |
|
|
|
|
|
|
|
|
0.96a |
22 |
May 1992 |
174,003 |
Stable |
4 |
|
|
|
|
|
|
|
|
0.96b |
22 |
June 1992 |
181,231 |
Stable |
2 |
|
|
|
|
|
|
|
|
0.96c |
5 |
July 1992 |
191,894 |
Stable |
2 |
|
|
|
|
|
|
|
|
0.97 |
1 |
August 1992 |
233,862 |
Developmental |
7 |
|
|
|
|
|
|
|
|
0.98 |
29 |
September 1992 |
320,917 |
Stable |
6 |
|
|
|
|
|
|
|
|
0.99 |
13 |
December 1992 |
426,483 |
Developmental |
79 |
|
|
|
|
|
|
|
|
Pre-1.0 |
6 |
March 1994 |
1,009,290 |
Pre-Release |
0 |
|
|
|
|
|
|
|
|
1.0 |
13 |
March 1994 |
1,016,601 |
Stable |
9 |
|
|
|
|
|
|
|
|
1.1.0 |
6 |
April 1994 |
1,013,691 |
Developmental |
95 |
|
|
|
|
|
|
|
|
1.2.0 |
7 |
March 1995 |
1,850,182 |
Stable |
13 |
|
|
|
|
|
|
|
|
1.3.0 |
12 |
June 1995 |
2,052,167 |
Developmental |
100 |
|
|
|
|
|
|
|
|
2.0-pre1 |
12 |
May 1996 |
4,570,261 |
Pre-Release |
13 |
|
|
|
|
|
|
|
|
2.0 |
9 |
June 1996 |
4,718,270 |
Stable |
39 |
|
|
|
|
|
|
|
|
2.10 |
30 |
September 1996 |
4,897,927 |
Developmental |
132 |
|
|
|
|
|
|
|
|
2.2.0-pre1 |
28 |
December 1998 |
10,455,343 |
Pre-Release |
8 |
|
|
|
|
|
|
|
|
2.2.0 |
26 |
January 1999 |
10,592,549 |
Stable |
19 |
|
|
|
|
|
|
|
|
2.3.0 |
11 |
May 1999 |
11,208,792 |
Developmental |
51 |
|
|
|
|
|
|
|
|
2.3.99-pre1 |
15 |
March 2000 |
16,027,466 |
Pre-Release |
8 |
|
|
|
|
|
|
|
|
2.4.0-test1 |
25 |
May 2000 |
16,989,873 |
Pre-Release |
11 |
|
|
|
|
|
|
|
|
2.4.0-Pre-release |
31 |
December 2000 |
19,341,926 |
Pre-Release |
0 |
|
|
|
|
|
|
|
|
2.4.0 |
4 |
January 2001 |
19,788,626 |
Stable |
4 and counting |
|
|
|
|
|
|
|
|