Howto: Use tar Command Through Network Over SSH Session

How do I use tar command over secure ssh session?

The GNU version of the tar archiving utility (and other old version of tar) can be use through network over ssh session. Do not use telnet command, it is insecure. You can use Unix/Linux pipes to create actives. Following command backups /wwwdata directory to dumpserver.backup.com (IP 192.168.1.201) host over ssh session.

The default first SCSI tape drive under Linux is /dev/st0. You can read more about tape drives naming convention used under Linux here.

# tar zcvf - /wwwdata | ssh root@dumpserver.backup.com "cat > /backup/wwwdata.tar.gz"OR# tar zcvf - /wwwdata | ssh root@192.168.1.201 "cat > /backup/wwwdata.tar.gz"

Output:

tar: Removing leading `/' from member names
/wwwdata/
/wwwdata/n/nixcraft.in/
/wwwdata/c/cyberciti.biz/
....
..
...
Password:

You can also use dd command for clarity purpose:
# tar cvzf - /wwwdata | ssh root@192.168.1.201 "dd of=/backup/wwwdata.tar.gz"
It is also possible to dump backup to remote tape device:
# tar cvzf - /wwwdata | ssh root@192.168.1.201 "cat > /dev/nst0"
OR you can use mt to rewind tape and then dump it using cat command:
# tar cvzf - /wwwdata | ssh root@192.168.1.201 $(mt -f /dev/nst0 rewind; cat > /dev/nst0)$
You can restore tar backup over ssh session:# cd /
# ssh root@192.168.1.201 "cat /backup/wwwdata.tar.gz" | tar zxvf -If you wish to use above command in cron job or scripts then consider SSH keys to get rid of the passwords.

Steps To Create A Startup Script

Steps to create a startup script

Step1:  Create a file

$ touch /etc/init.d/jira

Step2: Use your favorite editor ( eg: vi ) and past the below content into the file

#!/bin/sh



case "$1" in



start)

/opt/jira/startup.sh

;;



stop)

/opt/jira/stop

ps aux | grep java 

CSTOP=`echo $?`



if [ $CSTOP = 0 ]; then

sudo killall java

else



echo " Application is stopped"

fi

;;



restart)



$0 stop && sleep 5

$0 start



;;



reload)



$0 stop

$0 start

;;



*)



echo "Usage: $0 {start|stop|restart|reload}"

exit 1

esac

Step3: Change the file permissions

chmod +x /etc/init.d/httpd 

Step4 : Auto Starting application

 # update-rc.d apache2 defaults


Adding system startup for /etc/init.d/apache2 ...


/etc/rc0.d/K20apache2 -> ../init.d/apache2


/etc/rc1.d/K20apache2 -> ../init.d/apache2


/etc/rc6.d/K20apache2 -> ../init.d/apache2


/etc/rc2.d/S20apache2 -> ../init.d/apache2


/etc/rc3.d/S20apache2 -> ../init.d/apache2


/etc/rc4.d/S20apache2 -> ../init.d/apache2


/etc/rc5.d/S20apache2 -> ../init.d/apache2
 

Step 5: Manual start and restart of application

 /etc/init.d/jira start 

Recover MySQL Root Password

Step # 1: Stop the MySQL server process.

Step # 2: Start the MySQL (mysqld) server/daemon process with the --skip-grant-tables option so that it will not prompt for password.

Step # 3: Connect to mysql server as the root user.

Step # 4: Setup new mysql root account password i.e. reset mysql password.

Step # 5: Exit and restart the MySQL server.

Here are commands you need to type for each step (login as the root user):

Step # 1 : Stop mysql service

# /etc/init.d/mysql stop
Output:

Stopping MySQL database server: mysqld.

Step # 2: Start to MySQL server w/o password:

# mysqld_safe --skip-grant-tables &
Output:

[1] 5988
Starting mysqld daemon with databases from /var/lib/mysql
mysqld_safe[6025]: started

Step # 3: Connect to mysql server using mysql client:

# mysql -u root
Output:

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1 to server version: 4.1.15-Debian_1-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql>

Step # 4: Setup new MySQL root user password

mysql> use mysql;
mysql> update user set password=PASSWORD("NEW-ROOT-PASSWORD") where User='root';
mysql> flush privileges;
mysql> quit

Step # 5: Stop MySQL Server:

# /etc/init.d/mysql stop
Output:

Stopping MySQL database server: mysqld
STOPPING server from pid file /var/run/mysqld/mysqld.pid
mysqld_safe[6186]: ended
[1]+  Done                    mysqld_safe --skip-grant-tables

Step # 6: Start MySQL server and test it

# /etc/init.d/mysql start
# mysql -u root -p