In the past, to make an environment variable perminant, I would append to the /etc/profile file the environment variable for JAVA_HOME for example and update the PATH. While this does work, it has recently come to my attention that a more appropriate and easier method exists which does not involve editing the /etc/profile file. For this example, the environment variable,…
Read More » A particular virtual machine running Linux CentOS 6.5 had been problematic when it came to yum updates. The result always ended with a PYCURL ERROR 6 – Couldn’t resolve host. After spending way too much time towards resolution, a solution finally came to light. The configuration of the system is a Linux CentOS 6.5 build with two network cards. One…
Read More »For some time, the option to enable or disable javascript from within Mozilla Firefox was relatively easy to find. Although the option moved from place to place on the tool bar and in the menu options, the option was there. Since Firefox 23, this option was removed from an obvious place to the obscure. It has been suggested that this…
Read More »If yum updates or yum anything provides a network error or if you simply want to unregister the system from a managed server like RHN Classic, Red Hat Satellite, Katello, or Spacewalk, there is a only one file in the way. If presented with an error similar to this: To resolve delete one file. or gzip them temporarily. To revert…
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In an existing environment with Atlassian Confluence is installed, the likelihood of maintaining version updates as often as they should become available is generally unlikely. As these updates come to pass so does the diminishing possibility that an exported space from one installation may be imported into another installation. A case for importing spaces between installations would be for maintaining…
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VirtualBox will not start and present a Critical Error dialog box which reads “Failed to create the VirtualBox COM object. The application will now terminate.” If you select Details for additional information, it may offer something similar to this error, if not the same, Callee RC: CO_E_SERVER_EXEC_FAILURE (0x80080005). Here is a solution that worked in this case and will get…
Read More »Knowing the UUID (“Universally Unique Identifier”) of a device is important in the event of creating a permanent mount point using /etc/fstab. Of course, the name of the device may be used, however, using the UUID is the current trend. There are benefits to this trend. The identifier will likely not be used by anything else so that there will…
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The yum grouplist command can identify available package groups from the configured repositories. However, through a terminal window, the list is considerable when the language support is factored into the equation. For a Linux CentOS 6.4 x86_64 install, there are 206 package groups. Here are a few commands that may help. To determine the number of package groups that exist….
Read More »There are several commands that may be used to list the partitions of a Linux computer. Likely the most common one is the fdisk command. While it fdisk command is capable of just about anything, I am not always in the need to see all the information that listing the partitions provides, particularly when there are many partitions. So, I…
Read More »An example of a configuration file with many commented lines is /etc/sysctl.conf. If you wanted to display the contents of the file without the commented lines, the following command may be issued. However the resulting contents will be displayed with the remaining blank lines. To get around this one of a couple of commands may be issued. Source(s) http://stackoverflow.com/questions/18566169/match-empty-lines-in-a-file-grep http://stackoverflow.com/questions/3432555/remove-blank-lines-with-grep
Read More » Running Oracle’s VirtualBox on a Microsoft Windows 7 desktop to test applications and operating systems has proven to be very productive. As a result of a VPN connection using Citrix, a VirtualBox VM of CentOS 6.5 Linux could not connect to the remote network. After combing through the Internet, a solution is born. I know that there are many variables…
Read More »It was discovered days later that one of my websites was offline displaying only 500 error messages. As it turned out, it was as a result of the .htaccess files. The .htaccess files did not include <IfModule XXXXX> </IfModule> around the directives. Tracking down the offending lines, it was determined that the lines were all part of the mod_headers.c module….
Read More »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 Edit the /etc/sysconfig/vncservers file. Note that on the…
Read More »On a relatively fresh installation of Windows XP with SP2 on a Compaq Presqrio desktop running an AMD processor, Windows XP SP3 was applied. After an apparently successful installation, upon reboot, at the Windows XP logo, the system quickly flashed a blue screen of death and rebooted. Fortunately, I was able to login to the computer in safe mode to…
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 »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 »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…
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