ServerBuddies Support Blog

Verifying Signed Packages

All Red Hat Enterprise Linux packages are signed with the Red Hat GPG key. GPG stands for GNU Privacy Guard, or GnuPG, a free software package used for ensuring the authenticity of distributed files. For example, a private key (secret key) locks the package while the public key unlocks and verifies the package. If the public key distributed by Red Hat Enterprise Linux does not match the private key during RPM verification, the package may have been
altered and therefore cannot be trusted.

If the disc is mounted in /mnt/cdrom, use the following command to import it into the keyring (a database of trusted keys on the system):

To display a list of all keys installed for RPM verification, execute the following command:

The output will look similar to the following:

To display details about a specific key, use the rpm -qi command followed by the output from the previous command, as in this example:

kill - terminate a process

The command kill sends the specified signal to the specified process or process group. If no signal is specified, the TERM signal is sent.
The TERM signal will kill processes which do not catch this signal. For other processes, it may be necessary to use the KILL (9) signal, since this signal cannot be caught.

Most modern shells have a builtin kill function, with a usage rather similar to that of the command described here. The `-a’ and `-p’ options, and the possibility to specify pids by command name is a local extension.

Negative PID values may be used to choose whole process groups; see the PGID column in ps command out?put. A PID of -1 is special; it indicates all processes except the kill process itself and init.

EXAMPLES

kill -9 -1
Kill all processes you can kill.

kill -l 11
Translate number 11 into a signal name.

Installing Ruby on Centos with Yum

Ruby on Rails is an open-source web framework that’s optimizied for programmers happiness and sustainable productivity.

How to upgrade to the minimal requirement.

The below instructions are for 32-bit architecture.

RubyGems

You can download and then install RubyGems from:

http://rubyforge.org/projects/rubygems/

You will see a list of all files for the project.

yum-updatesd.conf - Configuration file

yum-updatesd uses a configuration file at /etc/yum/yum-updatesd.conf.

There is one section in the yum-updatesd configuration file, main, which defines all of the global configuration options.

Mail Options

email_to
List of email addresses to send update notification to. Defaults to ‘root@localhost’.

email_from
Email address for update notifications to be from. Defaults to ‘yum-updatesd@localhost’.

yum-updatesd, which provides notification of updates which are available to be applied to your system. This notification can be done either via syslog, email or over dbus.

Configuration is done via the /etc/yum/yum-updatesd.conf file.

Setup variables as follows:

IPV6 Network Configuration in Linux

Add nameserver to resolv.config

vi /etc/resolv.conf

Add line for ipv6 nameserver

vi /etc/sysconfig/network

Add a line at the bottom

vi /etc/sysconfig/network-scripts/ifcfg-eth0

Add lines at the bottom

Restart network services: