Often I find that I am needing to determine a) if an O/S install is 32bit or 64bit and b) if the CPU will support 64bit. I run into a lot of Linux boxes that have 64bit CPUs but the 32bit version of the distribution was installed. Here are a few quick ways to tell. For the O/S: The architecture should be listed as x86_64 for 64bit or i686 for 32bit. Using uname (-m or -p): 64bit $ uname -m x86_64 $ uname -p x86_64 32bit $ uname -m i686 $ uname -p i686 or using lscpu: 64bit $ lscpu | grep -i arch Architecture: x86_64 32bit $ lscpu | grep -i arch Architecture: i686 or using getconf: 64bit $ getconf...

With RPMForge you have access to over 5,000 additional packages, including  wine, vlc, mplayer, xmms-mp3, and other popular media tools. It is not part of CentOS but is designed to work with it. Installing RPMForge: Download the Package Install the GPG Key Verify the Package Install the Package Enjoy I generally prefer to work out of an “install” folder, it makes it easier for me to cleanup my mess and/or retain stuff that I install for later use elsewhere. $ mkdir install $ cd install/ $ wget http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el5.rf.x86_64.rpm $ sudo rpm...

Vimdiff starts Vim on two (or three or four) files. Each file gets its own window. The differences between the files are highlighted. This is a nice way to inspect changes and to move changes from one version to another version of the same file. See vim(1) for details about Vim itself. When started as gvimdiff the GUI will be started, if available. In each window the ’diff’ option will be set, which causes the differences to be highlighted. The ’wrap’ and ’scrollbind’ options are set to make the text look good. The ’foldmethod’ option is set to “diff”, which puts ranges of lines without...

Problems with your system time? So, you just got your new remote server setup, but something seems off? Oh, it’s the time. The times listed in your log files seem wrong, or maybe the modification time on your files. Perhaps your server is using the wrong time zone for your tastes. You can check by running the “date” command. $ date Wed Dec 5 05:59:11 UTC 2012 UTC? That’s not what I want! There’s a good chance the /etc/localtime is linked to the wrong timezone, or worse maybe it’s not linked at all. Maybe it’s a copy of the wrong time zone file? Well the fix is...

Sometimes you have servers hanging out in the public internet in ways that you have little control over the network and hardware firewalls. Setting up a hosted server, such as a Virtual Private Server (VPS) or “node” in the cloud can be scary. Fortunately software firewalls, such as iptables, can add a little to piece of mind. But, in these days of automated attacks, it is still not enough. Usually the primary means of access to these servers is SSH. There are a couple really simple things can be done to make SSH more secure. I recently setup a new node on Linode. In the first hour there...