This article describes the steps to change the system and hardware clock on linux without the need to use ntp. The steps described in this article are performed on CentOS 6. Current System Times & Dates The best way to get started is to find out the times which the system is currently using. One […]

Grep is a useful tool to filtering large quantities of data and acquiring just the data you need. In some circumstances the format of the data can be fine and it's easier to remove some other regular recurring lines that impact the structure of the data. Take the following as an example, this data was […]

This has been tried and tested on Fedora based distros. Forcing regeneration of host keys on Debian based distros may be different, you may need to use dpkg-reconfigure (dpkg-reconfigure openssh-server). If you are having issues with SSH such as errors staring SSH service and the log or journald complains about SSH host keys you can […]

Issue When Virtual Machine boots it complains that UUID's are incorrect. From dracut shell run the following: Now mount the primary disk: mount /dev/sda1 /mnt Or depending on what disk drivers you are using: mount /dev/vda1 /mnt Bind the directories which grub needs to detect the other operating systems: mount --bind /dev /mnt/dev && mount […]

If you get the following error when trying to login to an account on a Linux OS the likelihood is that the account has been locked out / expired: To re-enable an expired Unix account that has been locked out due to a timer you can run the following command via root or sudo user: […]

First change directory to the one containing the files you wish to bulk rename: Example of files inside of a directory: We are looking to remove everything but the unique string and the file extension at the end. For example "125 - Mexico - 39579375938789.jpg" would turn into "39579375938789.jpg". Lets try return a list of […]

RFC4821 proposes a mechanism to detect ICMP black holes and tries to adjust the path MTU in a smart way rather than performing DF set pings etc. On Linux implementation of this mechanism is pretty straightforward and on recent distributions it comes built into the OS by default. Enable TCP MTU Probing First check to […]