LVM Compression and Deduplication

With LVM / VDO, it is possible to save disk space using block-level compression and deduplication. I’ll show you how it’s done on Linux.

Enable zswap on memory-limited systems

On systems where memory is limited – be that a SOC compute or a low-end virtual machine, enable zswap gives you more usable memory. This is similar to Stacker which compress your data and let you have more space. Back in those days, hard drives were measures in MB!

NVME SSD lifetime

Wonder if your NVME SSD is reaching retirement age? Follow these simple steps to get an idea.

Using U2F key for sudo authentication

I got my U2F key for use with online accounts. It is cheaper than the popular Yubikey and it works well. Did you know you can use it for sudo or pam authentication? Here is how.

TLS1.3 on older linux distro

TLS1.3 is not commonly supported on older distro due to slow adaptation of new version of openssl. To get around that, we can compile libressl from source. Here is how I did it on AmazonLinux2.

Automatically update EL8

In EL7, we can use yum-cron to automatically install updates. On EL8, the equivalent tool is dnf-automatic. Here is how to set it up.

Load Averages on Linux/UNIX systems

Run RHEL8 on docker with Red Hat UBI image

Red Hat is offering a few official docker images for RHEL8. One can now use or build images based on the latest operating system from Red Hat. Here is how to do it in 3 simple steps

RHEL8 and Ansible

Red Hat EL8 is available now since May 7th. It’s not particularly exciting IMO. Many “new” features have been available on other distros quite a while ago. Here, I want to evaluate how easy it is to adopt my existing ansible playbooks on this new version of Red Hat.

UID > INT_MAX

From thehackernews, it was said when the UID is larger than INT_MAX, which is 2147483647, privilege validation is improperly handled and that gives the user right to run systemctl commands as if he/she is a privileged user. What is my INT_MAX? Though it’s hard to imagine who would use such an UID when they usually starts…