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CentOS cannot enter password at login interface because/etc/profile is not correct
Modify/etc/profile:
At the end add:
Export hadoop_home=/usr/local/hadoop-2.2.0
Export path=$PATH:$HADOOP _home/: $HADOOP _home/bin: $HADOOP _home/sbin
And then Source/etc/profile.
SSH Settings No password login
Under the current User:
SSH-KEYGEN-T RSA Direct return
Cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
chmod ~/.ssh
chmod 644 ~/.ssh/authorized_keys
That's fine, and then modify the/etc/hosts to correspond the IP to the hostname.
Centos installation JDK
: Download RPM or tar.gz on the JDK website
First step: Check if the Linux-brought JDK is installed (uninstall CentOS installed 1.4)
The installed CentOS will bring openjdk, with the command Java-version , will have the following information:
Java Version "1.6.0"
OpenJDK Runtime Environment (build 1.6.0-b09)
OpenJDK 64-bit Server VM (build 1.6.0-b09, Mixed mode)
It is best to uninstall the OPENJDK before installing Sun's JDK.
See Rpm-qa First | grep java
The following information is displayed:
java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5
Unloading:
RPM-E--nodeps java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
RPM-E--nodeps Java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5
There are some other commands.
Rpm-qa | grep GCJ
Rpm-qa | grep JDK
If OpenJDK source cannot be found, you can also uninstall this
Yum-y Remove Java java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Yum-y Remove Java Java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5
<1># rpm-qa|grep jdk← View JDK information or execute directly
Or
# rpm-q JDK
Or
# java-version
<2># Rpm-qa | grep gcj← Confirm version number of GCJ
<3># yum-y Remove java-1.4.2-gcj-compat← Uninstall GCJ
Step Two: Install the JDK
<1> Download from SunJdk-1_5_0_14-linux-i586-rpm.binor Jdk-1_5_0_14-linux-i586.bin
Create a new Java folder under/usr and place the installation package in the/usr/java directory
#Mkdir/usr/java
<2> Installing the JDK
# Cd/usr/java
①jdk-1_5_0_14-linux-i586-rpm.bin File Installation
# chmod 777 jdk-1_5_0_14-linux-i586-rpm.bin← modified to executable
#./jdk-1_5_0_14-linux-i586-rpm.bin← Select Yes to agree to the above agreement
#RPM-IVH jdk-1_5_0_14-linux-i586.rpm← Select Yes until installation is complete
②jdk-1_5_0_14-linux-i586.bin File Installation
# chmod a+x jdk-1_5_0_14-linux-i586.bin← enables the current user to have Execute permissions
#./jdk-1_5_0_14-linux-i586.bin← Select Yes until installation is complete
Step Three: Configure environment variables
<1># Vi/etc/profile
<2> Add the following lines at the end:
Export Java_home=/usr/java/jdk1.6.0_10
export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar
export path= $PATH: $JAVA _home/bin
<3># reboot← Restart machine configuration effective or source/etc/profile
Installing Eclipse 64-bit
CentOS Small white Command