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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

So You Think You Are Ready For The RHCSA Exam?

So you have studied hard, maybe even attended a week or two of formal training, for the Red Hat Certified System Administrator (RHCSA) exam and now you think you are ready to take the actual examination. Before you spend your money (currently $400) on the actual examination, why not download my custom CentOS 7.2 VM from and attempt a real world test of your RHCSA skills. This VM, which is in the form of an OVA (Open Virtualization Archive), will work with VMware Workstation 10 or later. Sorry, but if you want to use the VM in other environments,

Control Group Subsystems in RHEL7

Control groups (cgroups) are a Linux kernel feature that enables you to allocate resources — such as CPU time, system memory, disk I/O, network bandwidth, etc. — among hierarchically ordered groups of processes running on a system. Initially developed by Google engineers Paul Menage and Rohit Seth in 2006 under the name “process containers”, it was merged into kernel version 2.6.24 and extensively enhanced since then. RHEL6 was the first Red Hat distribution to support cgroups. Cgroups provide system administrators with fine-grained control over allocating, prioritizing, denying, managing, and monitoring system resources. A cgroup is a collection of processes that

RHEL7 Does Not Support User Namespace

The Linux kernel currently implements six (out of 10 proposed) namespaces for process separation: mnt – mount points, filesystems pid – processes net – network stack ipc – System V IPC uts – hostname, domainname user – UIDs, GIDs The last Linux namespace to be fully implemented was the user namespace (CLONE_NEWNS) whose implementation was finally completed in the 3.8 kernel after being started in the 2.6.23 kernel. The current kernel in RHEL7 is 3.10.0-121. Unfortunately it does not include the user namespace. According to Dan Walsh of Red Hat: We hope to add the user namespace support to a