3、Restart network service# service network restart 或 # /etc/init.d/network restart
重启network过程中可能会出现如下错误:
Error: Connection activation failed: Device not managed by NetworkManager
原因是:系统中有两个服务在管理网络,所以需要停掉一个,步骤如下:
1)Remove Network Manager from startup Services.
# chkconfig NetworkManager off
2)Add Default Net Manager
# chkconfig network on
3)Stop NetworkManager first
# service NetworkManager stop
4)and then start Default Manager
# service network restart
1、检测ssh是否启动,命令如下:
[iyunv@hadoopmaster home]# service sshd status
openssh-daemon is stopped
2、查看sshd是否已经是系统服务:
[iyunv@hadoopslaver ~]# chkconfig --list |grep sshd
sshd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
3、使用如下命令设置sshd服务自动启动:
[iyunv@hadoopslaver ~]# chkconfig --level 5 sshd on
[iyunv@hadoopslaver ~]# chkconfig --list |grep sshd
sshd 0:off 1:off 2:off 3:off 4:off 5:on 6:off
2、启动ssh,
[iyunv@hadoopmaster home]# service sshd start
Generating SSH1 RSA host key: [ OK ]
Generating SSH2 RSA host key: [ OK ]
Generating SSH2 DSA host key: [ OK ]
Starting sshd: [ OK ]
3、在master主机生成密钥并配置ssh无密码登入主机,步骤:
# cd /root/
#cd .ssh/ (如果没有.ssh目录则创建一个:mkdir .ssh)
1)生成密钥:
[iyunv@hadoopmaster .ssh]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
ec:d5:cd:e8:91:e2:c3:f9:6f:33:9e:63:3a:3e:ac:42 root@hadoopmaster
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| |
| . . = |
| S o = o |
| .E+ + . |
| .. =.. |
| . o+ *. |
| ..o+O++ |
+-----------------+
[iyunv@hadoopmaster .ssh]# ll
total 12
-rw-------. 1 root root 1675 Jul 10 16:16 id_rsa
-rw-r--r--. 1 root root 399 Jul 10 16:16 id_rsa.pub
2)将id_rsa.pub 拷贝到.ssh目录下,并重新命名为authorized_keys,便可以使用密钥方式登录。
[iyunv@hadoopmaster .ssh]# cp id_rsa.pub authorized_keys
3)修改密钥权限:
[iyunv@hadoopmaster .ssh]# chmod go-rwx authorized_keys
[iyunv@hadoopmaster .ssh]# ll
total 16
-rw-------. 1 root root 399 Jul 10 16:20 authorized_keys
-rw-------. 1 root root 1675 Jul 10 16:16 id_rsa
-rw-r--r--. 1 root root 399 Jul 10 16:16 id_rsa.pub
4)测试:
[iyunv@hadoopmaster .ssh]# ssh myhadoopm
The authenticity of host 'myhadoopm (192.168.80.144)' can't be established.
RSA key fingerprint is 2a:c0:f5:ea:6b:e6:11:8a:47:8a:de:8d:2e:d2:97:36.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'myhadoopm,192.168.80.144' (RSA) to the list of known hosts.
这样即可无密码进行登录。
5)远程拷贝密钥到slaver节点服务器:
[iyunv@hadoopmaster .ssh]# scp authorized_keys root@myhadoops:/root/.ssh
The authenticity of host 'myhadoops (192.168.80.244)' can't be established.
RSA key fingerprint is d9:63:3d:6b:16:99:f5:3c:67:fd:ed:86:96:3d:27:f7.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'myhadoops,192.168.80.244' (RSA) to the list of known hosts.
root@myhadoops's password:
authorized_keys 100% 399 0.4KB/s 00:00
6)测试master无密码登录slaver上:
[iyunv@hadoopmaster .ssh]# ssh hadoopslaver
[iyunv@hadoopslaver ~]# exit
logout
Connection to hadoopslaver closed.
[iyunv@hadoopmaster .ssh]#
[iyunv@hadoopmaster bin]# ./hadoop namenode -format
13/07/11 14:35:44 INFO namenode.NameNode: STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG: host = hadoopmaster/127.0.0.1
STARTUP_MSG: args = [-format]
STARTUP_MSG: version = 1.1.2
STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1 -r 1440782; compiled by 'hortonfo' on Thu Jan 31 02:03:24 UTC 2013
************************************************************/
13/07/11 14:35:44 INFO util.GSet: VM type = 64-bit
13/07/11 14:35:44 INFO util.GSet: 2% max memory = 19.33375 MB
13/07/11 14:35:44 INFO util.GSet: capacity = 2^21 = 2097152 entries
13/07/11 14:35:44 INFO util.GSet: recommended=2097152, actual=2097152
13/07/11 14:35:45 INFO namenode.FSNamesystem: fsOwner=root
13/07/11 14:35:45 INFO namenode.FSNamesystem: supergroup=supergroup
13/07/11 14:35:45 INFO namenode.FSNamesystem: isPermissionEnabled=true
13/07/11 14:35:45 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
13/07/11 14:35:45 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
13/07/11 14:35:45 INFO namenode.NameNode: Caching file names occuring more than 10 times
13/07/11 14:35:46 INFO common.Storage: Image file of size 110 saved in 0 seconds.
13/07/11 14:35:46 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/opt/data/hadoop/hdfs/name/current/edits
13/07/11 14:35:46 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/opt/data/hadoop/hdfs/name/current/edits
13/07/11 14:35:47 INFO common.Storage: Storage directory /opt/data/hadoop/hdfs/name has been successfully formatted.
13/07/11 14:35:47 INFO common.Storage: Image file of size 110 saved in 0 seconds.
13/07/11 14:35:47 INFO namenode.FSEditLog: closing edit log: position=4, editlog=/opt/data1/hadoop/hdfs/name/current/edits
13/07/11 14:35:47 INFO namenode.FSEditLog: close success: truncate to 4, editlog=/opt/data1/hadoop/hdfs/name/current/edits
13/07/11 14:35:47 INFO common.Storage: Storage directory /opt/data1/hadoop/hdfs/name has been successfully formatted.
13/07/11 14:35:47 INFO namenode.NameNode: SHUTDOWN_MSG:
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at hadoopmaster/127.0.0.1
************************************************************/
[iyunv@hadoopmaster bin]#
错误解决:
1、出现“PiEstimator_TMP_3_141592654 already exists. Please remove it first.”错误
[iyunv@hadoopmaster bin]# ./hadoop jar /opt/modules/hadoop/hadoop-1.1.2/hadoop-examples-1.1.2.jar pi 20 50
Number of Maps = 20
Samples per Map = 50
java.io.IOException: Tmp directory hdfs://myhadoopm:9000/user/root/PiEstimator_TMP_3_141592654 already exists. Please remove it first.
at org.apache.hadoop.examples.PiEstimator.estimate(PiEstimator.java:270)
at org.apache.hadoop.examples.PiEstimator.run(PiEstimator.java:342)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65)
at org.apache.hadoop.examples.PiEstimator.main(PiEstimator.java:351)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:68)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:139)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.util.RunJar.main(RunJar.java:156)