昨天弄oracle的备份，脚本中用到了scp，需要把服务器的数据cp到备份服务器上，需要配置oracle数据库服务器可以通过db_backup用户无密码登陆到备份服务器上，随便把ssh无密码登陆的配置步骤记下来了，下面是具体工程：

环境：

oracle数据库服务器：10.20.220.247

备份服务器：10.20.220.25

备份用户：db_backup

步骤：

1.在10.20.220.25上新建db_backup用户，指定家目录为/data/backup并设置密码
[root@localhost ~]# useradd db_backup -d /data/backup
[root@localhost ~]# passwd db_backup
Changing password for user db_backup.
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully.

2.确认sshd的配置文件的认证模块已打开

vi /etc/ssh/sshd_config

#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile     .ssh/authorized_keys

把上面三行的注释去掉

重启ssh服务

3.在10.20.220.247上

A.#ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa
Generating public/private dsa key pair.
Your identification has been saved in /root/.ssh/id_dsa.
Your public key has been saved in /root/.ssh/id_dsa.pub.
The key fingerprint is:
a4:a2:8e:58:e5:d3:38:92:00:c4:bf:a5:f9:67:af:ed root@localhost.localdomain

B.#cd .ssh/

#mv id_dsa.pub authorized_keys

#chmod 600 authorized_keys

4.在10.20.220.25上以db_backup登陆执行ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa

[db_backup@localhost ~]$ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa
Generating public/private dsa key pair.
Created directory '/data/backup/.ssh'.
Your identification has been saved in /data/backup/.ssh/id_dsa.
Your public key has been saved in /data/backup/.ssh/id_dsa.pub.
The key fingerprint is:
13:03:fd:46:2a:70:1d:a8:01:33:7b:c6:00:59:d2:a9 db_backup@localhost

5.在10.20.220.247上执行

scp -p authorized_keys db_backup@10.20.220.25:~/.ssh/authorized_keys

把db_backup的公钥拷贝到备份服务器上

6.测试

[root@localhost ~]# ssh db_backup@10.20.220.25
Last login: Mon Apr  2 03:14:34 2012 from 10.20.220.247
[db_backup@localhost ~]$ pwd
/data/backup

ok，成功了，

现在把的备份oracle脚本和备份文件的脚本加到crontab，每天晚1点二十上执行备份

[root@localhost ~]# crontab -e
20 1 * * * /data/SoftMgr_backup/db_bak.sh >/dev/null
20 1 * * * /data/SoftMgr_backup/file_bak.sh >/dev/null

oracle备份脚本内容：

[root@localhost SoftMgr_backup]# cat db_bak.sh
a=`date "+%Y_%m%d_%H%M"`
echo 'begin wcm database backup'
dmp_file=/data/SoftMgr_backup/db_back/$a.dmp
log_file=/data/SoftMgr_backup/db_back/$a.log
echo $dmp_file
echo $log_file

su - oracle -c "exp smdatadba/wpswps@smdata owner=smdatadba file=$dmp_file log=$log_file"

echo 'databse backup success,begin tar file'

cd /data/SoftMgr_backup/db_back
tar zcfP $a.dmp.tar.gz $a.dmp
tar zcfP $a.log.tar.gz $a.log

echo 'begin databse backup success,begin upload file to 10.20.220.25 /data/backup'
scp $a.dmp.tar.gz db_backup@10.20.220.25:~
scp $a.log.tar.gz db_backup@10.20.220.25:~
echo 'scp file end'

echo 'begin delete local file'
cd /data/SoftMgr_backup/db_back
pwd
rm -rf $a.dmp
rm -rf $a.log
rm -rf $a.dmp.tar.gz
rm -rf $a.log.tar.gz
echo 'operate end.'

#END