//进到用户.ssh目录下
[root@CentOS1 .ssh]$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/beifeng/.ssh/id_rsa): Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/beifeng/.ssh/id_rsa.
Your public key has been saved in /home/beifeng/.ssh/id_rsa.pub.
The key fingerprint is:
b4:0d:f7:cf:80:f8:86:dc:8d:75:2c:82:c6:06:6a:86 [email protected]
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| . o . |
| . . + B o . |
| E + S + = o |
| o + + = * |
| o = . o |
| . |
| |
+-----------------+
[root@CentOS1 .ssh]$ ll
total 8
-rw------- 1 beifeng beifeng 1675 Aug 16 13:13 id_rsa
-rw-r--r-- 1 beifeng beifeng 416 Aug 16 13:13 id_rsa.pub
想要登陆哪台计算机 就使用命令
ssh-copy-id 对方ip
集群搭建过程中的各种异常
2015-08-31 08:33:46,215 FATAL org.apache.hadoop.hdfs.server.datanode.DataNode: Initializa
tion failed for Block pool <registering> (Datanode Uuid unassigned) service to hadoop-senior02.ibeifeng.com/192.168.217.132:8020. Exiting.
java.io.IOException: Incompatible clusterIDs in /opt/modules/hadoop-2.5.0/data/tmp/dfs/data: namenode clusterID = CID-c13b3a84-bc83-4376-9d43-3c2748b51b64; datanode clusterID = C
ID-346aeb81-93e9-45a3-bf5d-7c3b15ad122d
at org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:477)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:226)
at org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:254)
解决方案
/opt/modules/hadoop-2.5.0/data/tmp/dfs/data 删除此目录
如果hdfs格式化得时候报如下异常信息：
Java HotSpot(TM) 64-Bit Server VM warning: You have loaded library /usr/local/hadoop-2.2.0/lib/native/libhadoop.so.1.0.0 which might have disabled stack guard. The VM will try to fix the stack guard now.
解决方法
在hadoop-env.sh和yarn-env.sh中添加如下两行：
export HADOOP_COMMON_LIB_NATIVE_DIR=${HADOOP_PREFIX}/lib/native
export HADOOP_OPTS="-Djava.library.path=$HADOOP_PREFIX/lib"
执行失败抛异常
java.net.UnknownHostException: CentOS2: CentOS2: 域名解析暂时失败
如果出现上述异常可以 vi /etc/hosts
可以把本机名称和ip配置进去