Linux

1. view the current virtual memory [root @ centos RPM] # Free-M total used free shared buffers cached mem: 1518 530 987 0 19 406 -/+ buffers/cache: 104 1413 swap: 2047 0 2047 2. view the current file system information[Root @ centos RPM] #

Today, I got a network cable connecting to the Intranet for my computer. After I plugged it into my computer, ifconfig turned out to be the original IP address. Do I have to restart the computer again? I don't want to restart the configuration of

Commonly used file search commands in Linux include which, whereis, find, locate, and type. The specific usage is not involved here, but the differences between them are compared. Which: searches for the location of a system command in the path

Use Yum install Java Yum install JDK The Java environment is installed. Use a text editor to write a Java program for verification and save it in the/search/bin directory. File Name: helloworld. java. Enter the following content:Public class

In Linux, there is a special feature-initializing the memory disk initrd (initial RAM disk) technology, and the kernel supports compressed file system images. With these two functions, we can enable the Linux system to initialize the memory disk

 Http://hi.baidu.com/%C0%CB%C2%FE%B5%C4%D0%A1%D0% AB %D7%D3/blog/item/1a3fef35202d4344251f1430.html In Linux, sysinfo is a struct used to obtain system-related information.Function Description and prototype:# Include int sysinfo (struct sysinfo *

Linux OS classifies the operating environment into the following seven levels: 0: boot (please do not switch to this level)1: text interface in Single User Mode2: multi-user text interface, does not have the Network File System (NFS) Function3:

1. Create a version library directory The created version library directory and installation directory are not in the same directory (you can create multiple versions. After creating the library, you must reconfigure the following items. Note the

From: http://hi.baidu.com/dog_freedom/blog/item/94744f1337026c59f819b843.html Smartmontools for SCSI hard drive: http://smartmontools.sourceforge.net/smartmontools_scsi.html Smartctl command parameter list: The following options are currently

Gpasswd commandFunction: Manage groupsUsage: gpasswd [-a user] [-D user] [-a user,...] [-M User,...] [-R] [-R] groupnameParameters:-A: Add a user to a group-D: delete a user from a group.-A: Specifies the administrator.-M: the specified group member

From: http://hi.baidu.com/zkheartboy/blog/item/6331d5cec964f60093457e0d.html A script for programming a Linux kernel module, which has not been written and is constantly updated... 1. Related commands0. view the kernel modules mounted by the

From: http://doc.linuxpk.com/41555.html   Author: SSS I. Module Introduction 　WindowsNT is a micro-kernel structure. Its functional blocks are divided into independent modules and there is a strict communication mechanism between these functional

Both SNAT (source address conversion) and DNAT (target address conversion) are developed to address network address insufficiency. Related Concepts: SNAT: source address translation, as the name suggests, is to replace the source address in the IP

Assume that Company A has registered a domain name net.cn on www.net.org and does not want to use hichina DNS servers. Instead, Company A wants to create two DNS servers, one as the master server and the other as the slave server.There are two

What is a firewall? Firewalls can be software such as 360, Jinshan, Kaspersky, or hardware. We can use the OSI Layer-7 model to divide the firewall. It can be divided: 1. layer-3 firewall: It is only responsible for checking whether the data flows

I learned the application of the Cluster two days ago. To sum it up, the cluster is not very difficult to understand. As long as I master its principles, it is not very difficult to implement it. Next, let's take a simple look at the

LVS-DNAT   Working principle: Change the destination address of a data packet before it enters the kernel)   The working mechanism of LVS is similar to iptables. Some work in the user space (ipvsadm) and some work in the kernel space. Installing

Drbd introduction: Drbd stands for Distributed replicated block (Distributed replication block device). It belongs to the device company but is completely open-source. It is a block-based file replication solution that is much faster than file-level

Last week, Marco talked about how to add a device module to Linux and implement the logon interface, level 1, and switch ON/OFF. By constantly switching to this small Linux system, we can gain a deeper understanding of the Linux system. Preparations:

Prerequisites: Make sure to install the following components. Otherwise, errors may occur when compiling some options.Legacy Software DevelopmentLegacy network serverX software developmentTo install MySQL, we directly use the binary package because