Kazila

Changing the default SSH port on your VPS – CentOS 5

This is not in anyway a game changer when it comes to security buy by simply changing your SSH port you can cut down on over 95% of automated brute force attempts. By default SSH utilizes the port 22; here’s how to change it to something else on CentOS:

Login into SSH and edit the sshd_config file which is located in /etc/ssh/.

nano /etc/ssh/sshd_config

Scroll down until you see the following line:

#Port 22

Delete the # symbol and change the 22 to a different port to your liking. It should look like this:

Port 5757

Save the file (CTRL-X), Y, and then enter. Finally, you just need to restart SSH

service sshd reload

Afterwards, it’s important to make sure you open up a new window and attempt to login to your virtual machine using the new port. If you messed things up, you can always login to SolusVM and update your configuration via console.

Test the Disk I/O on your VPS

There are a few commands that allow you to test the disk I/O speeds on your virtual machine. Please note that scores do vary and are not a completely accurate assessment of disk I/O.

dd if=/dev/zero of=/tmp/test bs=64k count=16k conv=fdatasync

Example output:

[root@server~]# dd if=/dev/zero of=/tmp/test bs=64k count=16k conv=fdatasync
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 4.89845 seconds, 219 MB/s
[root@server~]#


hdparm -t /dev/sda1

Example output:

[root@server~]# hdparm -t /dev/sda1
/dev/sda1: Timing buffered disk reads: 1158 MB in 3.01 seconds = 385.34 MB/sec
[root@server~]#

There is an ongoing thread posted on WebHostingTalk which will allow you to compare your score.

CentOS 5.5 + LAMP + Webmin Installation Tutorial

The goal here is to setup Apache, MySQL and PHP which is commonly referred to as a “LAMP” server. Everyone’s requirements are different but this will give you an easy way to get started. You will need a functional server with a fresh, clean installation of CentOS 5.5 to begin.

Installing Apache

You will want to utilize the yum repository for easy installation:

yum install httpd httpd-devel

Wait for the installation to complete then start up Apache:

/etc/init.d/httpd start

The location of the Apache configuration file should be located here: /etc/httpd/conf/httpd.conf
If not you can run the following command and SSH which should output the location:

whereis httpd.conf

Be sure to add the Apache daemon into startup so it runs automatically after a reboot:

chkconfig httpd on

Installing MySQL (latest version)

Utilize the yum repository again for quick and easy installation:

yum install mysql mysql-server mysql-devel

Then run the MySQL daemon:

/etc/init.d/mysqld start

Add the MySQL daemon into startup so it runs automatically after a reboot:

chkconfig mysqld on

If you want to make sure MySQL is running, run the following command:

ps aux | grep mysql

This step is of unnecessary but it’s just in case you run into any issues.

For security purposes, you will want to change the MySQL root password through the MySQL console:

mysql

The console should open, then run the following:

mysql> USE mysql;
mysql> UPDATE user SET Password=PASSWORD('password') WHERE user='root';
mysql> FLUSH PRIVILEGES;

Note: be sure to change the (‘password’) to your liking.

To login into MySQL as root run:

mysql -u root -p

Once you are logged in you can create a database. I am going to use “blog” as the database name and add the user “john” with full privileges:

mysql > create database blog
mysql > GRANT ALL PRIVILEGES ON blog.* TO 'guest'@'localhost' IDENTIFIED BY 'john' WITH GRANT OPTION;
mysql> USE mysql;
mysql> UPDATE user SET Password=PASSWORD('password') WHERE user='john';

And that’s it for MySQL!

Installing PHP

Install PHP through yum with some required modules. These can be changed to meet your requirements but should be sufficient for most setups:

yum install php php-mysql php-common php-gd php-mbstring php-mcrypt php-devel php-xml

By restarting Apache, PHP should fire up:

/etc/init.d/httpd restart

Your “public_html” folder or “www” folder is located in the /var/www/html/ directory. To test and see if PHP is working, you will want to create a PHP file with the following code:

I normally call this file, phpinfo.php. You can then access the file through your IP address (eg. http://IPADDRESS/phpinfo.php)

You will want to install phpMyAdmin for easier MySQL DB management. To install simply run:

yum install phpmyadmin

Then access phpMyAdmin through the following URL: http://IPADDRESS/phpmyadmin

Installing Webmin (Latest Version)

First download the RPM:

wget http://prdownloads.sourceforge.net/webadmin/webmin-1.540-1.noarch.rpm

Then run the following command:

rpm -U webmin-1.540-1.noarch.rpm

The rest of the install will be done automatically to the directory /usr/libexec/webmin, the administration username set to root and the password to your current root password. You should now be able to login to Webmin at the URL http://localhost:10000/. Or if accessing it remotely, replace localhost with your system’s IP address.