All Articles

mkisofs: Repackaging a Linux Install ISO

In the office I use Red Hat quite often and one of the quicker ways to provision a Red Hat server is via kickstart. There are many ways to reach a kickstart file during initial install (NFS, HTTP, FTP) but one of the ways I commonly use is to put the file on the installation DVD itself. The below steps are what I use to add a custom directory to the installation iso file.

EMC PowerPath: superblock could not be read

Recently while working on a system that uses EMC PowerPath, I ran into a little issue after rebooting. The Issue fsck.ext3: No such file or directory while trying to open /dev/emcpowera1 /dev/emcpowera1: The superblock could not be read or does not describe a correct ext2 filesystem. The Cause The root cause of this issue is pretty simple when a Linux system boots it performs file system checks on file systems listed within the /etc/fstab file.

Websphere MQ Cheat Sheet for System Administrators

IBM’s Websphere MQ is a middle-ware application that allows two applications to pass messages back and forth without having to integrate with each-other directly. Websphere MQ is a fairly popular application in the enterprise especially for those running many java based programs. Today’s article is a copy of my personal Websphere MQ cheat sheet. This cheat sheet is geared more from a System Administrators prospective and doesn’t touch much on creating or altering queues or channels, but should provide a good head start for those who need to just get something restarted.

Installing MySQL on Ubuntu/Debian

MySQL is the most popular open source relational database management system (RDBMS) in the world. MySQL is used by everyone from the simple small business website to the large internet giants like Facebook, Google or Amazon. In fact the contents of this page are even stored within MySQL. Installing MySQL is a fairly common task for any systems administrator; especially if that administrator is running a standard LAMP stack (Linux, Apache, MySQL & PHP/Python/Perl).

NFS: Setting up a basic NFS file system share

While there are many distributed file systems out there; especially with the rise of cloud & virtual computing. The Network File System or NFS protocol has by far held its title as an easy to use, fast to implement and very efficient distributed file system. In today’s article I will be covering how to set up a basic NFS share. This article will assume that you have already created a file system, if not hop over to this article and then come back for the NFS steps.

Cheat Sheet: Cutting Text with cut

The cut command is a Unix/Linux tool used to literally cut text from files and output from other commands. With the cut command a user can take text and output only certain parts of the line. In my opinion cut is the most under recognized and utilized command in Linux/Unix. This is mostly due to the fact that when most Sysadmins want to cut text from files or standard output many will reach for AWK.

Cheat Sheet: Crontab by Example

Today’s article may be pretty basic for regular readers but hopefully some may find it useful. This article will cover creating a crontab entry and show some examples of common crontabs. The Cron daemon is a service that runs on all main distributions of Unix and Linux and specifically designed to execute commands at a given time. These jobs commonly refereed to as cronjobs are one of the essential tools in a Systems Administrators tool box.

Advanced Linux System Statistics and Diagnostics with SystemTap

In one of the first posts of this blog I covered some basic SystemTap functionality from an email that I sent to members of my team, but I have always felt that I haven’t given SystemTap as thorough of an article as this incredible tool deserves. Today I want to correct that. For today’s article I will show how to compile SystemTap scripts on one server while running the compiled module on a production server without installing debug-info or devel packages in production.

xargs: Build and Execute Commands with Arguments from Standard Input

For me when it comes to useful commands xargs ranks along side commands like find, top and df; xargs is a great time saver and incredibly useful. Today I will show a few examples of usage and some of the lesser known features. Basic Usage The xargs command is used to take the output of one command and provide it as arguments to another. Example (xargs): # ls [0-9]-test.

Cheat Sheet: 21 useful find commands

For todays article I wanted to put together a quick little cheat sheet for some GNU find command examples. Some of these commands will be basic some will be more advanced, but they all will be useful. As a caveat some commands don’t work in all Unix environments and this is especially true with older releases. If you find yourself in one of those situations there is a way to make the find command work you will just need to use different methods like the -exec flag.