Question : Recently, I was learning how to secure Apache web server guide – in which one of the suggestion was to load only necessary modules in Apache, as that will reduce the server load and improves the web server security as well. I would like to know if there’s any command that…
I have been using Request Tracker version 3 for quite sometime and it worked great. But suddenly the RT server crashed and the Apache error log had the below error message: Attempt to free unreferenced scalar: SV 0x811ef70, Perl interpreter: 0x7f5a010 at /usr/lib/perl5/5.8.8/ExtUtils/Liblist.pm line 6. Segmentation fault It seemed like…
OpenStack is a great platform to setup your own cloud environment. But for novice, it’s not that easy. Yes, there are plenty of packages such as RDO, Packstack, Devstack etc..that allows you to install OpenStack in few minutes, but until you install it manually you are never going to understand…
WordPress is an amazing platform to build your website or a blog. It’s powerful, easy to install, loaded with features, active community, millions of plugins etc…But…it’s also the platform loved by hackers. You can install WordPress in just 2 minutes, but your job should not stop there. There are plenty…
If you are getting this error “Permission denied: /var/www/html/.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable“. Then here’s how you can fix the issue. Solution: Apache web server uses distributed configuration files via .htaccess (that provides access control for various parts of the filesystem). When httpd is…
If your PHP program throws this warning “Module <some_module_name> already loaded”, then here’s how you can fix that. Normally this warning message is seen when you execute PHP program in the command line – as below: $php sam.php PHP Warning: Module ‘fileinfo’ already loaded in Unknown on line 0 You…
Everyone might have used RAR files in Windows, but using it on Linux is not straightforward. None of the Linux operating systems (by default) comes with an utility to process RAR files. It means, if you have downloaded any RAR file from internet and want that to be opened or extracted…
Question: Hi, I have installed Xen Hypervisor version 3.1 on RHEL machine, which runs two CentOS VMs on Dom0. I would like to use xenstore to write some information in Dom0 (for instance, I want to store/write hostname of Dom0) and read that store in DomU. After reading out some forums,…
Question: I was able to install Xen Hypervisor successfully on Red Hat Enterprise Linux release 5.5 and booted the system with xen kernel as well. But while starting the xend service, I get this error message “/proc/xen/capabilities: No such file or directory“. I see a folder ‘xen’ inside /proc, but ‘capabilities’…
Question: I was trying to install Xen server on CentOS 6.4 via yum install xen, but yum failed with an error message as “Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again“. How to solve this? Snapshot of the error: # yum install centos-release-xen Loaded plugins:…
Question: My company’s intranet website hosts GB’s of software tools and applications. I have been trying to download all of those via wget command and yet maintain the same directory structure (the source directory has organized tools under various categories, which I like maintain it same). Here’s an example of…
Question: I have a Red Hat Enterprise Linux version 5.5 operating system running on an Intel Xeon machine that supports VTx. I would like to know how to install Xen virtualization software and launch a guest virtual machine on top of it? Answer: Xen is an Open Source software that…
Occasionally, you might want to move your Mail folder from one location to another. For instance, all of my Thunderbird mails were stored in C drive, thus occupying most of the disk space out there and that forced me to move out all the mails from C drive to D drive….
Hi, I was using setup command in one of my RHEL machine to configure firewall, network and system services. Recently, I bought a CentOS vps, which doesn’t seem to have setup command installed. I tried ‘yum install setup‘, but the command terminated with a message ‘Nothing to do’. Can you let…
Without a doubt, Microsoft Office is one of the most popular application out there. Recently I came across a quick tip that lets you to extract images from DOCX, XLSX, PPTX formats. We do plenty of documentation for various projects, which might include lot of screenshots and images. If you…
Question: I installed OpenStack Icehouse on my test bed and was able to create instances successfully. But I was not able to login to CentOS instance via PuTTY using the key file (.pem). However, I was able login via SSH command. Can someone tell me how to login to instance…
The reason is simple! The visitor on your webpage wants the important content to load first and visible immediately (and so does the search engines). Here’s a simple scenario – Let us assume that a user lands on your web page via Google and immediately wants to read the content that…
Question: I was trying to setup Apache web server on a different port other than port 80. For instance, on port 81, but the httpd daemon refused to start on port 81 and thrown an error message as “httpd already running”. Though, I verified that the port is changed from 80 to…
The Emojis are cool, loved and used by many WordPress authors. But there are few, like me, who don’t use Emojis. Starting from version 4.2, WordPress supports Emoji’s by default. It means, an extra Javascript file gets added to your site’s header to support 4 bit unicode characters. Interestingly, the feature will…