Considering that data is backed up on the local machine, once the machine's hard disk fails, the data cannot be taken out. Remote manual data backup is time-consuming and time-consuming. The best way is to use scripts to implement remote automatic mutual backup. However, a password is required for remote login through SSH or file copying through scp. To overcome this problem, you first need to implement SSH login without a password, so that you can use rsync, scp, rexec and other commands for remote backup. 1. Set ssh login without A password. The method is as follows: assume that the server A and server B need
Considering that data is backed up on the local machine, once the machine's hard disk fails, the data cannot be taken out. Remote manual data backup is time-consuming and time-consuming. The best way is to use scripts to implement remote automatic mutual backup. However, a password is required for remote login through SSH or file copying through scp. To overcome this problem, you first need to implement SSH login without a password, so that you can use rsync, scp, rexec and other commands for remote backup.
1. Set ssh login without a password. The method is as follows:
Assume that the server A and server B needs to log on to server B with root instead of entering the password on server A. follow these steps:
1) generate A key pair on machine A and execute the following command:
Ssh-keygen-t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/. ssh/id_rsa):/root/. ssh/id_rsa
Enter passphrase (empty for no passphrase): Press Enter
Enter same passphrase again: Press Enter
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:
F6: 61: a8: 27: 35: cf: 4c: 6d: 13: 22: 70: cf: 4c: c8: a0: 23 root @ host1
In this way, id_rsa and id_rsa.pub are generated under the/root/. ssh/path, where id_rsa is the key and id_rsa.pub is the Public Key www.linuxidc.com.
2) Copy id_rsa.pub generated on machine A to machine B. Assume that it is copied to the temporary directory of machine B, for example:
Scp/root/. ssh/id_rsa.pub root@218.242.214.20:/tmp
3) log on to machine B with the root account, go to its home directory, create the authorized_keys file, and set the permissions.
Cd ~ /. Ssh
Cat/tmp/id_rsa.pub> authorized_keys
Chmod 400 authorized_keys
Rm-f/tmp/id_rsa.pub
4) test
Go to the root account on machine A and try to log on to machine B. Check if the password is not required.
Note:
The authorized_keys File Permission is very important. If it is set to 777, you still need to provide a password when logging on.
Remember to delete id_rsa.pub in the temporary directory to make it a good habit.
This method is successfully tested on Red Hat9.0.
2. Edit the crontab file
Vi/etc/crontab
For example, set to execute the script in cron. daily at every day:
00 3 *** root run-parts/etc/cron. daily
3. Edit the script in cron. daily.
Cd/etc/cron. daily/
Vi backupdb
Pg_dump-U postgres voipack>/voipack. SQL
Pg_dump-U postgres regserver>/regserver. SQL
Tar-cvjf/aavm.tgz.bz2/usr/local/aavm
Tar-cvjf/Oracle.tgz.bz2/var/oracle
Scp/voipack. SQL root@218.242.214.20:/root/218.242.214.23 _ backup
Scp/regserver. SQL root@218.242.214.20:/root/218.242.214.23 _ backup
Scp/aavm.tgz.bz2 root@218.242.214.20:/root/218.242.214.23 _ backup
Scp/oracle.tgz.bz2 root@218.242.214.20:/root/218.242.214.23 _ backup
Copy the backup file generated on 23 to the path 218.242.214.20:/root/218.242.214.23 _ backup.
In the same way, data on server B can be backed up to server A to implement dual-host mutual backup.