Linux

1. Basic Concepts.Java_mem_opts= "-server-xmx2g-xms2g-xmn512m-xx:permsize=128m-xss256k-xx:+disableexplicitgc-xx:+ Useconcmarksweepgc-xx:+cmsparallelremarkenabled-xx:+usecmscompactatfullcollection-xx:+usefastaccessormethods-

2.2Bash Command-line basic operations[user @ host ~]$ #//$ #为提示符 $ for normal user #代表root用户 ~ Represents the current directory su-//switch to root userLS//list equivalent to dos dir displays the current directory listUname//Returns the current

Raid:Common RAID levels:RAID 0:Operating mode: The data is striped first, and then stored to the hard disk.Space utilization: 100%Whether redundancy is supported: noPerformance: Disk IO increased (depending on the number of disks)Requires at least 2

1. Create: LN [-s] source target, with-S is a soft connection, otherwise a hard connection;2. The soft connection has the independent Inode index, the hard connection and the source file share inode index;3. The hard connection can only point to the

Reprint http://blog.chinaunix.net/uid-20554039-id-3035417.htmlWe often find a file in Linux, but we do not know where to put it, you can use some of the following commands to search. These are the information found from the Internet, because

1.userdel [-r] Username: Delete User, user thought data has,/etc/passwd,/etc/shadow,/etc/group,/etc/gshadow,/home/username,/var/spool/ Mail/username, Parameters1) Delete together with the user's home directory2.finger [-S] Username: query

SCP 10.25.133.184:/usr/local/zabbix-2.4.1.tar.gz/usr/local1, in order to security considerations Zabbix only use the ordinary user to run, if your current user is called Ttlsa, then you run him, he then uses Ttlsa identity to run. But if you run

Command functionShutdown-h now shutdown commandStartX into the graphical interface (if your redhat has a desktop installed), X is the X-window desktopShutdown-r now reboot (or use reboot)VI Editor use (in fact, VI is very powerful, shortcut keys are

From the beginning of this article, to http://www.longene.org/download/ download tmqq is in use, the other QQ2013 download the game Oh, try it yourselfFirst, describe your system configuration: win8+ ubuntu14.04LINUXQQ are available in a variety of

Basic linux network knowledge and linux network knowledgeIfconfigIfdown Nic device name stop a NIC DeviceIfup Nic device name enable a NIC DeviceView the network status: netstat t lists tcp port u lists udp port n does not use domain names and

Makefile resolution (the simplest LED), makefile resolution led ① Led_sp.bin: start. o led. o # Led_sp.bin is generated by start. o and led. o. ② Arm-linux-ld-Ttext 0x0-o led_sp.elf $ ^ Set the start address of led_sp.elf to 0x0.   ③

CentOS study notes -- time, centos study notes --Time Anyone who has installed a Linux system may have this experience, that is, the time required for installing the windows system on this machine is correct, but after installing the linux system,

Install Java jdk1.7.0 _ 10 in CentOS6 The installation procedure is as follows: 1. Download JDK7.0 _ 10 (jdk-7u10-linux-i586.tar.gz) Address: 2. Uninstall the built-in open source JDK Check whether JDK is installed rpm -qa | grep java The following

Linux Account Management1. Add a userAdd User using useradd command useradd [-c comment] [-d home_dir] [-e expire_date] [-f inactive_time] [-g initial_group] [-G group[,...]] [-m [-k skeleton_dir] | -M] [-n]

Use iptables in CentOS to speed up and limit the number of connections per IP Address Step 1: Establish an adsl connection, which is available in system settings-network settings. It is easy to handle in the graphic interface. Step 2: Enable IP

Centos6 install mysql using yum Check whether MySQL is installed. --> run the following command:Rpm-qa | grep mysqlUninstall installed MySQL --> run the following command:# Rpm-e -- nodeps mysql-libs -*Delete all files in the/var/lib/mysql

Web tracking applications in UbuntuApplication of Webbench in Ubuntu environment 1. Overview Webbench is a well-known website stress testing tool. Webbench can test the performance of different services on the same hardware and the running status of

Linux performance monitoring free Free is used to display the memory usage of the system, which is confusing with the free output. The following is a summary: 123 4 5 6 The output result of the free command is from the file/proc/meminfo, which is

JMeter Installation and Use in Windows Linux1. Test in Windows environment 1. Download: Address: http://apache.fayea.com//jmeter/binaries/apache-jmeter-2.12.zip2. open: Run jmeter. bat in the bin directory.3. Use: 0>. Add a thread group to the test

Solve the problem that Linux crontab does not execute ntpdate Preface: In our project, we need to synchronize the Time of the Linux server. So we used the ntpdate command and configured it in crontab to synchronize the time of every hour, after that,