Significance of Linux kernel version

In Linux, there is a directory named "/usr/src/kernels/". The following shows a Linux Kernel File, for example, 2.6.18-164. el5-x86_64, 2.6.18-8. el5-x86_64 and 2.6.18-194. el5-x86_64 and so on, what do these file numbers mean? For example, what does 2.6.18 mean? What does EL5 represent? What does x86_64 mean?

Classification of Linux kernel versions

There are two types of Linux kernel versions: stable version and development version. The Linux kernel version number consists of three groups of numbers: the first group of numbers. The second group of numbers. Group 3 Numbers

The first group of numbers: the current kernel main version.

The second group of digits: the even number indicates the stable version, and the odd number indicates the development version.

The third group number: the number of times the error is fixed.

Example 1: 2.6.18-128. elsmp,

Number in the first group: 2, major version number

Number 6 in the second group. The minor version number indicates a stable version (because an even number exists)

The third group number 18 indicates the number of modifications. The first two digits can be combined to describe the kernel series. For example, the stable version 2.6.0 is the kernel series of version 2.6. 128: indicates the 5th patch fine-tuning of the current version, while elsmp indicates that the current kernel is elsmp specially tuned El: Enterprise Linux; SMP: indicates that multi-processor is supported, indicates that the kernel version supports multiple processors.

Elsmp and El and SMP in Linux Kernel

In Linux, elsmp indicates that the current kernel is elsmp specially tuned El: Enterprise Linux; SMP: indicates that multi-processor is supported, indicating that the kernel version supports multi-processor.

Example 2: When Red Hat Linux is started, the grub Startup menu has two options:

Red Hat Enterprise Linux ES (version number. Elsmp)

Red Hat Enterprise Linux es-up (version number. El)

In fact, this is the difference between a single processor and a symmetric multi-processor to start the core file when the system is started.

Red Hat Enterprise Linux ES (version number. Elsmp) multiple processor (symmetric multiprocessing)

Red Hat Enterprise Linux es-up (version number. El) uniprocessor

Linux digits

We know that the current CPU is mainly divided into 32-bit and 64-bit, of which 32-bit can be divided into: i386, i586, i686, and 64-bit CPU is called x86_64, this is because different levels of CPU command sets are different, so some of your software may be optimized by your CPU, therefore, the software is divided into i386, i586, i686 and x86_64. In the current CPU market, most of them insist on 64-bit software.

 

Source: http://www.linuxidc.com/Linux/2012-11/74440.htm