Image of XSLT 2.0 and XPath 2.0 Programmer's Reference (Programmer to Programmer)
Image of Linux Kernel Development (3rd Edition)
Image of Advanced Programming in the UNIX Environment, Second Edition (Addison-Wesley Professional Computing Series)
Image of Beginning Google Maps API 3

Configure a Host ISO-based Package Repository on a CentOS 7.2 VM

In a recent blog post, I demonstrated how to set up a local RPM repository (repo) in a VMware CentOS 7.2 VM (AKA guest) running under VMware Workstation (AKA the host.) This made the CentOS VM independent of the need for network access w.r.t. RPM package installation. However, the trade off for the ability to install packages without Internet access is the 6 GB plus increase in the size of the VM necessitated for storing all the packages and metadata. Consider the following alternative scenario. You have downloaded the CentOS-7-x86_64-Everything-1511.iso from the CentOS Project or a mirror, used the ISO

RHCSA Preparation - Script to Configure a Simple OpenLDAP Server

The ability to quickly configure an LDAP (Lightweight Directory Access Protocol) client for accessing user and group accounts is one of the skills you are expected to have when you sit the Red Hat RHSCA exam. LDAP is a application-level protocol for accessing and maintaining distributed directory services over an IP-based network. It is specified in a series of RFCs (Request for Comments) using ASN.1. The latest LDAP specification is Version 3, published as RFC 4511. Typically, at a minimum, LDAP is used to facilitate centralized user and group account administration. Instead of storing user and group account information locally

Nesting RHEL7 KVM on VMware Workstation 12

Recently I wished to build a Red Hat Enterprise Linux 7 (RHEL7) appliance with 2 KVM-virtualized guests. Essentially a type 2 hypervisor (VMM) on top of another type 2 hypervisor. I installed RHEL7 on VMware Workstation 12 and configured it as a Virtualization Server. It was a smooth install without any issues. However I was surprised to find that KVM (Kernel-based Virtual Machine) simply did not work at all and lsmod did not even list the KVM kernel modules. It turns out that you need to do two changes to your RHEL7 guest configuration file in order for KVM support

Fastest Way to Gain Root Access in RHCSA7 Exam

Time is at a premium during the RHCSA exam. Every minute you can save on a task is a minute as it can be applied to some other task. If you have to reboot the operating system, that is wasting time as you cannot be doing anything useful in terms of task completion during the reboot. One critical task is to require you to gain root access to the installed and running operating system. This is typically the first thing you need to do in the exam. There are many blogs and write-ups on how to do this by modifying

My Thoughts on Systemd on RHEL7

From the earliest days of systemd, I have been opposed to the technology as far as it’s use on enterprise servers is concerned. Now that RHEL7 (Red Hat Enterprise Linux v7), which uses systemd instead of upstart, is starting to replace older versions of RHEL in enterprise and DOD environments, I thought I would revisit the issue. My technical reasons for opposing systemd on servers are as follows: There is no guarantee that services will be started in the same order each time a server is rebooted. Logs are binary, non-transactional and in a different format than previously. This means