Transferring Files using Netcat

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Netcat is a great cross platform tool, it can be used for just about all things related to or involving TCP or UDP. Its most practical use is transferring files using Netcat from one machine to another via a network. Where non *nix people usually don’t have SSH installed or set-up, it is much faster to transfer files using Netcat than setup SSH. Netcat is just a single executable, and works across all platforms (Windows,Mac OSX, Linux).

On the Netcat receiving end

This will start Netcat listening on port 1234.

On the Netcat sending end

This will connect to the receiver and begin transferring files using Netcat.

If you’d like to transfer files quicker (*nix only I am afraid), you can compress the file during sending process

On the Netcat receiving end

On the Netcat sending end

Install yum priorities on CentOS

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The Yum Priorities plugin can be used to enforce ordered protection of repositories, by associating priorities to repositories.

The priorities plugin is a useful tool if properly configured, and used with an understanding of the functionality and a recognition of the limitations and potential issues. It can be used in conjunction with the ‘exclude’ and/or ‘includepkg’ options, as well as the ‘enabled=0’ option to disable a repo by default. This can let you choose which packages a less important repo will supersede those of a more important one.

Install Yum Priorities

Continue reading “Install yum priorities on CentOS”

CentOS Warning: RPMDB altered outside of yum

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Yum is an automatic updater and package installer/remover for rpm-based systems. It automatically computes dependencies and figures out what things should occur in order to safely install, remove, and update rpm packages. Yum also efficiently and easily retrieves information on any package installed or available in a repository to the installer.

When trying to update your server via the yum command you might see the following error / warning message:

Warning: RPMDB altered outside of yum.

Total download size: 28 k
Installed size: 53 k
Is this ok [y/N]: y
Downloading Packages:
nethogs-0.8.0-1.el6.x86_64.rpm | 28 kB 00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction

Warning: RPMDB altered outside of yum.

Installing : nethogs-0.8.0-1.el6.x86_64 1/1

Installed:
nethogs.x86_64 0:0.8.0-1.el6

Complete!

How do you fix this problem?

+George Rushby

CentOS Change Timezone

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After installing CentOS we sometimes see that the date is not in our desired timezone, instead it defaulted to the PST timezone.

Correcting your timezone is an easy operation, so here is a quick guide to change your CentOS timezone configuration file.

Firstly you’ll need to know your timezone and/or country, a list can be found in /usr/share/zoneinfo/

The more generic procedure to change the timezone is to create a symlink to file /etc/localtime

OR you can copy and replace the current localtime setting

To verify that your timezone is changed use the date command: