vNugget
RHEL & CentOS Tutorials, Cheat-Sheet and Tips
Well, I successfully took my Red Hat Certificate of Expertise in High Availability Clustering exam (EX436) on 10 November to renew my existing RHCE certification. Through this post I will share my preparation and exam experience. Preparation Nothing can substitute experience on the subject but to be sure to have addressed all the required exam
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,
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
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.
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
Configuring central logging is one of many important thing that you should configure to secure your system, it allow you to have an exact timeline in case of an incident or for troubleshooting reason. I was in the process of configuring some machines to send their logs to a remote system, the thing is that
Last week I was experimenting with a Squid proxy server configuration and trying to see if I can get better performance, I still have a lot to do, but I thought it will be more interesting to publish my configuration and see if someone can take it to the next level and share his experience.
Situation where you need to shrink lvm partition or file system are rare due to the plenty of storage space we have nowadays, but first let’s clarify one thing, the correct term is this : some time we need to shrink, reduce or resize an LV (logical volume) file system, which can be an ext3,
Linux interface card can get lost after a restore operation using netbackup. If you can’t restore your interfaces, and you end up adding new ones, their MAC address will be different from the old interfaces you had and they will get a different name. I was in a situation where I have to restore a