Password Complexity and Account Lockout

This will be a brief blog post on how to use pam module on CentOS or Red hat 6.x to enforce password complexity and account lockout, the account locking will also be enabled through ssh. You can use passwdqc (which is no longer supported on RHEL7) or cracklib pam module to enforce the password complexity, […]

How to Use Special Characters on a Virtual Machine Console

The virtual machine console won’t allow you to write some special characters using some keyboard layout. As stated by this VMware KB 2071245. On my French keyboard, I was able to bypass this limitation using this keyboard combination: Alt + Alt Gr. The affected characters can include, but are not limited to: / (slash) \ […]

How To Change The CPU governor

Performance tunning is one of the most exciting and complicated subject at the same time, it’s complicated because if you change one setting it might affect the others so you must have a deep understanding of the what, how, why and the why not of other aspect of the operating system that you would like […]

Honored To Be Awarded a vExpert 2017!

Well I wasn’t expecting this one! For me it’s an honor to be awarded a VMware vExpert 2017. I’m taking it as an encouragement to continue and provide great work for the community, with a busy schedule it’s really hard to keep up with updating the blog. As I think we are in a busy world, […]

Zoning an ESXi to an XtremIO Storage Array

The task is relatively easy if you have some background on storage but I wanted to take note of it in this blog post as I don’t do this on a daily basis. Once you connect your ESXi to the storage array you don’t have much to do after that except on some cases when you […]

Start-ttys main process (8475) terminated with status 1

I had a trouble with a Linux box after we lost access to our storage array, the system switched to a read only file system. Everything stopped working, no command was recognized, no possibility to remount the file system in RW. After a reboot, some LV got in inactive status and no file system mounted. […]

Changing the vSphere Web Client Display Language – English

Almost everyone in the technical field is comfortable with using the English language for their daily tasks. As you know, managing future version of VMware vSphere will only be possible with the Web Client. If you have already used the old trick to change the language of the java vSphere client like this: “C:\Program Files\VMware\Infrastructure\Virtual […]

vSphere API Example for Testing Guest Credentials

While experimenting with the vSphere API using the Python pyvmomi SDK, I was wondering if there is any way to test guest credentials after I have reset a user password, so the main idea is to automate all the process of resetting the root password on a linux virtual machine. If you haven’t read my […]

How To Use Sed To Replace a Specific String in a File

Let’s take the linux shadow file as an example. Using sed you can replace the root user password with an empty character. Suppose your /etc/shadow file look like this: [root@localhost ~]# cat /etc/shadow root:$6$GE3JYGgDvt5jloXN$l0cNhqsh8564GHsdSgUGz79Cqm2ml.Q0xmtgSDyUVdJRHrgFIWPd0QKB02RedspqunU4yYS0/xDI0fcZgEGt.::0:99999:7::: You can use the following sed command to replace the root password string between the two semicolon with an empty string. […]

CentOS 7: Firewalld Command Line Cheat Sheet

I was working on my CentOS 7 box to get familiar with some new functionalities, as you know RHEL 7 and CentOS 7 come with many changes in many aspect. To have a quick reference for many of this changes, I will try to document some basic command on managing my system, so let start […]