centos administration

Change the maximum file descriptor of CentOS and maximum file descriptor of centos File descriptors are a type of system resources. Linux manages system resources in a hierarchical manner. System-level management:/proc/sys/fs/file-max sets the maximum number of files that can be opened by the system.You can view the value as follows:[Root @ # panda ~] # Cat/proc/sys/fs/file-max655351[Root @ # panda ~] # Sys

CentOS modifies the server system time and centos modifies the server After linux is installed, it is generally a foreign world. It is not convenient to set tasks at all, or the website gets local time out of order. Therefore, you need to change the server time to the same as the local time, that is, the time for changing to China. First Command: date-s '2017-10-31 10:10:10 'Second command: clock-w // wri

Build xl2tp server in CentOS 7.2 and build xl2tp in CentOS # Download the xl2tpd.tar.gz source code package '''Wget http://pkgs.fedoraproject.org/repo/pkgs/xl2tpd/xl2tpd-1.3.8.tar.gz/d244fdcd88f64601b64b7302870afca8/xl2tpd-1.3.8.tar.gz''' #2. Install xl2tpd and libreswan '''Tar-zxvf xl2tpd-1.3.8.tar.gzCd xl2tpd-1.3.8Make make installIf "contrib/pfc. c: 14: 23: Fatal error: pcap-bpf.h: No file or directory

How to install gcc in centos 7 and gcc in centos 7 System Environment:Centos7.4 When Nodejs8.7 is installed today, a warning is reported: WARNING: C ++ Compiler too old, need g ++ 4.9.4 or clang ++ 3.4.2 (CXX = g ++) Then, check the version installed on your system: 4.8.5. Okay, you can't use yum for upgrade. you can install it manually. 1. Select the version to be upgraded Gcc ftp LIST (I selected 5.4.

CentOS 7 network configuration (1), centos Problem description: After CentOS7 is installed, the local IP address cannot be found using the ifconfig command.Unable to access the InternetYou cannot log on using SSH. Go to the/etc/sysconfig/network-scripts/directory/ Use the ls command to view the NIC configuration file name Use vim to edit the file Change ONBOOT = no in the last line to ONBOOT = yes

Centos vi copy and delete the cut paste command, centos Paste Copy: Yy: copy the current row Nyy: Number of copied rows (including the current row ). Assume that three rows are copied, And the cursor is positioned at the position of Row 3. If you enter 3yy, 1 ~ is copied ~ 3 rows of content Copy multiple rows in another way: (start row, end row co paste position), for example, copy 3 ~ Paste the content

Modify hostname in Centos and hostname in centos 1. Temporary modification with commands Hostname oier In this way, the hostname of the server becomes oier, but it will change back after restart. 2. Edit the configuration file for permanent Modification Vi/etc/sysconfig/network HOSTNAME = oier It takes effect after being restarted. ==================================== Host resolution Modificati

How to check Centos context switching: centos Context1. What is Context Switch )? Context switching, also known as process switching or task switching, refers to switching the CPU from one process or thread to another process or thread. The operating system can run multiple processes at the same time. However, a single CPU can only execute one task at the same time. The operating system uses time slice rota

Restore rm from CentOS and rm from centos I. Mount the disk partition as read-only This step is very important, and the disk should be mounted as read-only as soon as possible after the file is deleted by mistake. The sooner you start the process, the higher the chances of successful recovery. 1. Check the partition in which the deleted file is located. [root@localhost~]#mount/dev/mapper/VolGroup-lv_root o

system as much as possible, or a library where Yum sources can be installed, such as GD, Libpng, Libjpeg, Libfreetype ... Everything, the CentOS source is ready, we just want a different version of PHP. Since we need the source code to compile PHP, so we need to install the corresponding source version, and with the Devel logo version. yum install libpng libpng-devel libjpeg-turbo libjpeg-turbo-devel freetype freetype-devel gd In the PHP source direc

Linux CentOS MySQL database installation and configuration tutorial, centos installation and configuration tutorial Notes on installing the mysql database A) download the mysql source installation package: wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm B) install mysql Source: yum localinstall mysql57-community-release-el7-8.noarch.rpm If the end of a complete appears !, The MySQL

How to upgrade python to python 2.7 Under centos 5.x, centos 5.xpython2.7 First download python2.7.3 from the official website, compile and install itCopy codeThe Code is as follows:$ Wget http://www.python.org/ftp/python/2.7.3/Python-2.7.3.tgz$ Tar zxvf Python-2.7.3.tgz$ Cd Python-2.7.3$./Configure$ Make make installBack up the original python and connect python2.7 to the new location.Copy codeThe Code is

Enable iptables firewall for CentOS and iptables for centos In fact, these things should be clearly written as soon as they are completed. They have been written for a long time. Maybe they have not been written in some places. I hope to see the kids shoes for help and I will update them again, if any error occurs, please criticize and correct it. I used iptables as a firewall before 7.0 and firewall after

CentOS configures firewall operation instances (enable, stop, enable, and disable ports) and centos instances Basic firewall operation commands Query the Firewall Status: [root @ localhost ~] # Service iptables status Stop firewall: [root @ localhost ~] # Service iptables stop Start firewall: [root @ localhost ~] # Service iptables start Restart firewall: [root @ localhost ~] # Service iptables rest

://localhost:5000; Proxy_http_version 1.1; Proxy_set_header Upgrade $http _upgrade; Proxy_set_header Connection keep-alive; Proxy_set_header Host $host; Proxy_cache_bypass $http _upgrade; }}Perform nginx-s reload or systemctl restart Nginx to restart Nginx after configuration is completeThen access port 80This time the visit found it possible to report 502, find a long way to find a solutionCause: SELinux configuration issues.Workaround: Turn off SELinux.Input: sestatus , if SE

Reprint please indicate the source: http://blog.csdn.net/l1028386804/article/details/51537000 These configurations are based on VMware network Adapter VMnet8, assuming that my VMware network Adapter VMnet8 IP address is 192.168.106.1 The following figure: My Ifcfg-eth0 file is configured as follows: Device=eth0 type=ethernet uuid=f9f0898c-bf2c-4183-857a-eab291cd904d onboot=yes NM_CONTROLLED= Yes bootproto=static ipaddr=192.168.106.130 netmask=255.255.255.0 broadcast=192.168.106.255 gatew

Download the response version of the YUM source on the MySQL official network: http://dev.mysql.com/downloads/repo/yum/# download Source $wgethttp//dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm# Installation Source $ rpm-IVH mysql57-community-release-el7-9. noarch.rpm# installed MySQL, will auto-install dependent software $Yum Install-Y mysql-server# Modifying MySQL configuration file $VI/etc/my.cnf# Modifying or shutting down the MySQL password policy (optional line): Validate_pa

MySQL installation tutorial in centos 7, centos 7 MySQL How to install MySQL in centos 7 Install MySQL There are two differences between mysql and windows. 1) Save my. ini to/etc/my. ini 2) User Permissions, executed by individual users 1. Check whether mysql has been installed before. Run the following command: Rpm-qa | grep-I mysql If the following package is d

Redhat provides a Redhat-upgrade-tool upgrade tool;[1] Configuring the software source # vim/etc/yum.repos.d/upgrade.repo[upgrade]name=upgradebaseurl=http://dev.centos.org/centos/6/upg/x86_64/enable =1gpgcheck=0 [2] Installing software tools Yum-y Install preupgrade-assistant-contents Redhat-upgrade-tool preupgrade-assistant [3] Check for potential issues before upgrading

CentOS (13) for Linux -- installation and configuration of Mysql database under CentOS6.4, centos -- centos6.4 To develop j2ee on Linux, you must first build a j2ee development environment, including jdk, tomcat, and eclipse installation (this article has explained in detail CentOS (7) of Linux learning-building a j2ee environment under