Making YUM Faster

Question: When I run updates with YUM (an update tool for Redhat, CentOS, or Fedora Linux), it seems like it takes forever. How can I make it faster?

Answer: Although there many things to consider when trouble-shooting speed issues, one specific YUM concern might be the speed of the mirror sites used for downloading packages. If download time seems to be the main concern (as opposed to actual installation time), installing yum-fastmirror should help.

This simple program will automatically seek out the fastest YUM mirror servers and then store the metadata in /var/cache/yum/timedhosts.txt. The plugin works by timing all the servers that come up in the mirror list and then selecting the one that is fastest for your location. Locations closer to you on less congested servers usually connect and send data faster. With yum-fastmirror, this can all be configured automatically.

To install the plugin, enter as root:

yum install yum-fastmirror

Setting the Correct Date for Your Linux Server

Question: My dedicated server is showing a different timezone than my home computer. How can I set it to be on my timezone.

Answer: Generally speaking it does not matter if your remote server is on a different timezone. It will still function, but when scheduling maintenance, upgrades, and backups, it is crucial to make sure the time you schedule and announce is the actual time of the server. With the Linux “date” command, you can display and set the time of your server.

To display the current day, date, time, timezone, and year, simply type “date” from the command line. To set a new time, type “date -s” or “date –set” followed by the date, time, or both. For example, to set the time to 11:15:00, enter:

date +%T -s "11:15:00"

Changing the actual timezone is a little more involved. Read more about that here. In Redhat Enterprise Linux, Fedora, or CentOS, however, simply type:

redhat-config-date

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The "setup" command in Redhat, Fedora, and CentOS

In Linux, most server configuration files are located in /etc. Most of them are text files, and although it is fairly easy to edit them, Redhat-based distributions have a handy graphical ncurses program that allows the dedicated server system administrator to handle certain tasks.

The program is simply called setup and is available by default in Redhad Enterprise Linux, Fedora, and CentOS. It includes the following options:

Authentication – Password management and configuration
Firewall – Setup iptables and determine which ports to allow through the firewall
Keyboard – This one is not relevant on a remote server
System service – Decide which services are started when the system boots
Timezone – Set the correct timezone for the server (very important for websites with dynamic content)
X configuration – For the graphical X system, not normally relevant on a remote server.

Understanding Linux Services

In a Linux-based operating system, a service is a program that can be executed at startup and run in the background. The user can also execute it at any time from the command line. On a Linux dedicated server, services are very important, as most of the critical applications are run in this manner.

In most Linux distributions, services are found in /etc/init.d. To find out what commands can be executed for a given service, such as rsync, simply login as root and enter the following:

/etc/init.d/rsync

It will respond telling you how you can use it:

Usage: /etc/init.d/rsync {start|stop|reload|force-reload|restart|status}

Therefore, to start rsync, you would enter:

/etc/init.d/rsync

In Redhat Enterprise Linux, CentOS, and Fedora, you can run the following:

su - [then enter the root password]
service rysnc start

You can apply the same formula to any service, such as apache (httpd) or sendmail, but be sure you know which services you are enabling or disabling before you try them.

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