Linux

Run "rm-rf/*" in SSH. If you do not understand this command, all Linux system files may be deleted. This DELETE command can be executed only for accounts with the "root" permission. Other accounts without the "root" permission can only delete files

When the system slows down, we may first focus on the cpu metrics. Sometimes we find that the cpu usage is not high at all, but the system is still stuck, in this case, you may need to consider another thing that affects performance-the disk's IO

CentOS System Startup Process POST (power-on self-check): Hardware DetectionUnder the control of the CPU, map a program in the RAM chip to the ROM address space, and execute the commands to check the health status of the system hardware, for

1. Download The epel-release-6 source package from the sohu image and install it. Wget http://mirrors.sohu.com/fedora-epel/6/x86_64/epel-release-6-8.noarch.rpm [Root @ centos64 fedora-epel] # ls Epel-release-6-8.noarch.rpm [Root @ centos64

To download and install the Server Installation Package, select the correct installation package.1. CentOS-6.4-x86_64-LiveCD.iso (LIVE: Health Check version)2. CentOS-6.4-x86_64-LiveDVD.iso (LIVE: is a health check version, with some software

My centos 5.5 NIC Driver is r8169, and the latest driver is r8168 on the official website. This makes me feel weird. Doesn't r8169 represent the driver version, or r8169 is not officially developed. Just in case. The following describes how to

Chkconfig Name:Chkconfig-updates and queries runlevel information forsystem services updates the running level information of the query system service. Syntax: chkconfig [-- add] [-- del] [-- list] [System Service] Chkconfig [-- level ] [System

Sed Introduction sed is a non-interactive editor. It does not modify the file unless you use shell redirection to save the results. By default, all output rows are printed to the screen. Sed editor processes files or inputs row by row and sends the

In actual work, the company does not directly give the root user to the employee, but temporarily obtains the root permission of the system through the employee's own account. 1. My current test environment is: red hat linux 6 [Root @ rhel1 xcg] #

I. New users and user groups: useradd and groupadd 1. useradd parameters: -U: indicates the UID mark. -D: Specifies the home directory. The default value is/home/user name. -E: Specifies the Account expiration time (this option is also available in

1. Put the following content to the end of/etc/profile (some systems such as CentOS 5.5 may need to end with/etc/bashrc) HISTFILESIZE = 2000 HISTSIZE = 2000 exportHISTTIMEFORMAT = "% Y % m % d-% H % M % S:" exportPROMPT_COMMAND = '{command =

To use temporary files, consider the following:Ensure that the file names of temporary files do not conflict with each other.Ensure that the contents of temporary files are not peeked, deleted, or modified by other users or hackers.The mkstemp and

YUM proxy settings: OK edit/etc/yum. conf. After adding # Proxyproxy = http: // username: password @ proxy_ip: port, you can also use proxy_username and proxy_password to configure the proxy user name and password, all users use a Global Proxy when

1. Firewall Introduction 1. functions: 1) determine whether data packets can pass through the firewall through the source port, source IP address, source MAC address, specific port in the packet, destination port, IP address, and MAC address. 2)

Comments: Common CentOS commands that are frequently used in our work have been carefully organized.The following describes common CentOS commands.I. View cpu using common CentOS commandsCopy the Code as follows:More/proc/cpuinfo | grep "model

1. Users and user groups store files 1./etc/passwd Each row of records corresponds to one user, and each row of records is separated by a colon (:) into seven fields. The format and meaning of each field are as follows: [Cpp] view plaincopyprint?

Forward the port XX that accesses the local machine to the port of another machine.Net. ipv4.ip _ forward = 1 in the vi/etc/sysctl. conf configuration file. The default value is 0, which allows iptalbes FORWARDI directly edited the file and changed

1. install the software packageInstall related software packages for dig and nslookup. Centos:# yum install bind-utilsDebian:# apt-get update# apt-get install dnsutilsIn addition, you must set the dns server IP address in/etc/resolv. conf before

/Bin binary executable command/Dev special file/Etc system management and configuration fileConfiguration files and scripts started by/etc/rc. dThe base point of the/home user's home directory. For example, if the user's home directory is/home/user,

To bind a CentOS dual-nic, you can use two NICs to virtualize an Eni (which must be supported by a switch). The aggregated device looks like a separate Ethernet interface device, in general, two NICs have the same IP address, and parallel links are