After searching through several guides, all complete in one way or another, however, not complete enough, I put the pieces together into this guide. This particular configuration is a basic VNC server with two users. After creating the second user, the process can be repeated for additional users. Install the VNC Server yum install tigervnc-server -y Edit the /etc/sysconfig/vncservers file….
Read More »CentOS, Scientific Linux (“SL”), and Oracle Linux are all based on the Red Hat Enterprise Linux (“RHEL”) code base. Though there are differences between them, the similarities are more than not. For whatever the reason, there are documented processes that permit the conversion from one of the aforementioned Linux distros to another. This conversion will document another approach based on…
Read More »GPG keys are stored in the /etc/pki/rpm-gpg directory, as part of the CentOS 6/RHEL 6 install. Looking though the contents of this directory, files like RPM-GPG-KEY-CentOS-release exist. To actually use the key to verify packages, it must be imported. The following command provides the contents of /etc/pki/rpm-gpg ls /etc/pki/rpm-gpg | xargs -n1 basename RPM-GPG-KEY-CentOS-6 RPM-GPG-KEY-CentOS-Debug-6 RPM-GPG-KEY-CentOS-Security-6 RPM-GPG-KEY-CentOS-Testing-6 There are two…
Read More »Instead of having to distribute an image file with a shell script that called for the file, an idea came to mind to embed the image into the shell script. Although one way was found, I devised an alternate simpler method to distribute the image file embedded in the script. The first method uses four lines of code. This method…
Read More »vsftpd (“Very Secure FTP Daemon”) is an FTP server for Linux and supports PAM (“pluggable authentication modules”). A virtual user cannot login to the Linux system and is considered more secure than using a “real” user whom can login to a Linux system. This guide offers a script that demonstrates yet another way to setup a vsftpd server using PAM…
Read More »Hyperic is a tool that offers visibility into applications and infrastructure across physical, virtual, and cloud environments. It consolidates discovery, monitoring, analysis and control of application, system, and network assets. Hyperic is available as vFabric Hyperic, the commercial version, and as Hyperic HQ, the open-source version. While similar, vFabric Hyperic offers additional features over the open source version. What this…
Read More »Script or batch file writing can be very rewarding, especially when the script written works as planned. What is particularly rewarding is when a shortcut is found that greatly simplifies how the script is written and executed. Here is a couple of shortcuts that I picked up from the Internet. The end result all seem to be the same. This…
Read More »Several years ago, I wrote a set of instructions how to install JBoss on a RHEL / CentOS Linux operating system. Then, the procedure utilized the GUI, mouse clicks, and the terminal. Well, as my comfort level with Linux has grown, so has the instructions into a script. A prerequisite for JBoss is Java JDK. For JBoss 5.1.0.GA, I elected…
Read More »While in the process of updating a development virtual machine of CentOS 5.6, it became clear that the updates would not update CentOS 5.6 to it’s final release of CentOS 5.9. The traditional yum update approach produced the status of No Packages marked for Update. However, a couple of additional commands produced the desired result of CentOS 5.9. The traditional…
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After installing CentOS 6.2 i386 minimal ISO as a VMware virtual machine, immediate attempts to perform a yum update failed. The virtual machine network is bridged to the host computer. Pings to the router were successful, however, after some Internet searches, a solution that remediated this situation was found. Before getting to the “fix”. An attempt to change the network…
Read More »When decompressing a compressed tar file, generally, the approach is to change directory to the root and execute the tar command from there with a full path to the compressed tar. There is an easier method that will remove a line or two of code from each script. Down to a single command line. This is how to use tar…
Read More »This has more applications than with just the chkconfig command. However, I found this script to be useful and wanted to add it to my database of useful scripts. This script will chkconfig off the services listed in the services variable. #!/bin/bash # chkconfig-services-off.sh # # Add services here services=”vsftpd yum-updatesd vncserver sendmail” arr=$(echo $services | tr ” ” “\n”)…
Read More »Suppose you wanted to determine the length of time it took to complete the execution of a bash script. Rather than sitting in front of the computer and estimating the time elapsed by watching the script execute with a stopwatch, it can be done with a few lines of code. Near the top of the script add the following variable…
Read More »From the man pages, chkconfig is defined to provide a simple command-line tool for maintaing the /etc/rc[0-6].d directory hierarchy by relieving system administrators of the task of directly manipulating the numerous symbolic links in those directories. When chkconfig is run without any options, it displays usage information. If only a service name is given, as in the case above, it…
Read More »When using if then statements in your scripts, these statements will likely take up multiple lines. Sometimes, you may want a simple if then statement and would prefer to write only one line of code. This is a quick tip I picked up the other day. It is a simplification and explanation off how to combine multiple lines of code…
Read More »There was a CentOS server where the IP address needed to be changed. Searches through the Internet revealed a series of commands that would do the trick. This script incorporates these commands into a single utility or bash script. This may not be all inclusive, but it did work for me on a CentOS 5.8 server. To use this script,…
Read More »There was a CentOS server where the name needed to be changed. Searches through the Internet revealed a series of commands that would do the trick. This script incorporates these commands into a single utility or bash script. This may not be all inclusive, but it did work for me on a CentOS 5.8 server. To use this script, simply…
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