1. The installation type of centos 6 system is described as follows:
Desktop: The basic desktop system, including commonly used desktop software, such as document viewing tools.
Minimal Desktop: A basic desktop system with less software included.
Minimal : The basic system, without any optional packages.
Basic Server : Platform support for the installed base system, excluding the desktop.
Database Server: Basic system platform, plus mysql and PostgreSQL databases, no desktop.
Web Server: Basic system platform, plus PHP, Web server, and mysql- and PostgreSQL database clients, no desktop. Virtual Host: Basic system plus virtualization platform.
Software Development Workstation: Contains many software packages, basic systems, virtualization platforms, desktop environments, and development tools. (1440 installation packages)
2. The meaning of the Linux kernel (kernel) version number
There is a directory /usr/src/kernels/ under linux that records the kernel files of a linux system.
For example: 2.6.18-164.el5-x86_64
There are two types of Linux kernel versions: stable version and development version. The Linux kernel version number consists of 3 groups of numbers: the first group of numbers. The second set of numbers. The third set of numbers
First set of numbers: The current major release of the kernel.
Second set of numbers: even numbers represent stable releases; odd numbers represent in-development releases.
Third set of numbers: The number of bug fixes.
Example 1: 2.6.18-128.ELsmp,
The first set of numbers: 2 , the major version number
The second set of numbers: 6 , the minor version number, indicating the stable version (because there are even numbers)
The third group of numbers 18, the revision number, represents the number of revisions, and the first two numbers together can describe the kernel series. Like the stable version 2.6.0, it is the 2.6 kernel series.
128: Indicates the 5th fine-tuning patch of this current version, and ELsmp indicates that the current kernel is specially tuned for ELsmp EL: Enterprise Linux; smp: Indicates support for multiprocessors, indicates that the kernel version supports multiprocessors
ELsmp and EL and smp in the linux kernel
Under linux, ELsmp points out that the current kernel is specially tuned for ELsmp EL: Enterprise Linux; smp: indicates that it supports multi-processor, indicates that the kernel version supports multi-processor
Example 2: When Red Hat Linux boots up, the GRUB boot menu will have two options, namely
Red Hat Enterprise Linux ES (Version No. ELsmp)
Red Hat Enterprise Linux ES-up (Version No. EL)
In fact, this is the system boot by GRUB boot - the difference between uniprocessor and symmetric multiprocessor startup core files.
Red Hat Enterprise Linux ES （版本号。ELsmp） multiple processor （symmetric multiprocessing ）
Red Hat Enterprise Linux ES-up (Version No. EL) uniprocessor
3. linux order
The current CPU is mainly divided into 32-bit and 64-bit, of which 32-bit can be divided into: i386, i586, i686, and the 64-bit CPU is called x86_64, this is because different levels of CPU command sets are different, so your Some software may perform some optimizations on your CPU, so the software will be divided into i386, i586, i686 and x86_64. In the current CPU market, most of them stick to 64-bit software.