Normally on this blog I tend to write about more complicated tasks or fancy Linux tricks and completely overlook some of the most basic tasks that a SysAdmin needs to know. Today I have decided that I will make my blog a little more comprehensive and add some posts with some of the basics.
Along with this I will be starting a new category, called Sysadmin Basics and I will try to post an additional article each week that covers some of the more basic concepts and commands used by Linux and Unix Sysadmins.
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.
Recently I was compiling a list of Linux commands that every sysadmin should know. One of the first commands that came to mind was nmap.
nmap is a powerful network scanner used to identify systems and services. nmap was originally developed with network security in mind, it is a tool that was designed to find vulnerabilities within a network. nmap is more than just a simple port scanner though, you can use nmap to find specific versions of services, certain OS types, or even find that pesky printer someone put on your network without telling you.
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.
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.
Since I've mostly been using Red Hat or the gui desktop of Ubuntu lately I've neglected to notice the transitions from the sysVinit packages to systemd. Recently I installed Fedora 16 and was a little surprised when chkconfig didn't work anymore. I decided I would write a post that gives the systemctl version of a few common chkconfig commands.
List processes chkconfig:
# chkconfig --list systemd:
# systemctl list-units Enable a service chkconfig: