Linux and Unix tutorials for new and seasoned sysadmin
Linux and Unix tutorials for new and seasoned sysadmin
I‘ve an CentOS based server and Ubuntu based desktop pc. I’m connecting to my CentOS using ssh X11 forwarding feature. However, speed over the Internet is pretty slow for certain apps such as VMWare console. How do I speed up OpenSSH X11 forwarding using Linux / UNIX desktop system?
Q. I’m moving my server from local data center to another data center. I’ve new server up and running. My site is dynmic and I’d like to transfer MySQL database from old server to new server. How do I make transfer smooth and successful?
A. The best and secure way is to use ssh to transfer database to another server. You need to use following tools:
=> SSH client
=> SSH Server on remote box
=> mysqldump command
=> UNIX pipes
Let us say you would like to Transfer MySQL database called foo to remote box called bar, enter the following command at shell prompt:
$ mysqldump foo | ssh user@remote.box.bar.com mysql foo
You can just copy table called chocolate (from recipe database) to remote database called icecream using same syntax:
$ mysqldump recipe chocolate | ssh user@remote.box.com mysql icecream
Q. I’ve HP-UX installed on my HP UX UNIX server. But I’m not able to start or restart the OpenSSH ssh server. How do I stop or restart sshd under HP-UX?
A. HP-UX Secure Shell uses Pluggable Authentication Module for password authentication. Server configuration file is located at /opt/ssh/etc/sshd_config.
/sbin/init.d/secsh {start|stop}
/etc/rc.config.d/sshd
Type the command:
# /sbin/init.d/secsh stop
Type the command:
# /sbin/init.d/secsh start
Q. I have just installed Ubuntu 6.06 and I would like to allow remote login to my system from home via ssh. How do I install and configure SSH server?
A. OpenSSH is a FREE version of the SSH connectivity tools that technical users of the Internet rely on. Users of telnet, rlogin, and ftp may not realize that their password is transmitted across the Internet unencrypted, but it is. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks. Additionally, OpenSSH provides secure tunneling capabilities and several authentication methods, and supports all SSH protocol versions.
Type the following two command to install both ssh client and server:
# sudo apt-get install openssh-server openssh-client
To be frank your server is ready by default. Just test it from your home computer or from same system with the command:
# ssh localhost
OR
# ssh user@your-server-ip-address
Assuming that your server hostname is userver.mydomain.com and username is vivek, you need to type the following command:
# ssh vivek@userver.mydomain.com
To stop ssh server, enter:
# sudo /etc/init.d/ssh stop
To start sshs server, enter:
# sudo /etc/init.d/ssh start
To restart ssh server, enter:
# sudo /etc/init.d/ssh restart