This evening I’m trying to enable EPEL repository on a RHEL 9 server, by following instruction is taken from How to install EPEL on RHEL and CentOS Stream article [1] by Red Hat Enable Sysadmin. Enable the CodeReady Linux Builder repository. $ sudo subscription-manager repos --enable \ codeready-builder-for-rhel-9-$(arch)-rpms Repository 'codeready-builder-for-rhel-9-x86_64-rpms' is enabled for this system. Install the EPEL RPM. $ sudo dnf install \ https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm ...snip... Installed: epel-release-9-7.el9.noarch Complete! Let’s try to install htop (available from the EPEL repo) to verify that everything is working: $ sudo dnf install htop -y ....

One joy of being parents when your children are in higher grade (say year 4 or 5) is that you’ll get a chance to review math lesson again in order to explain or help your children with their math problem. Nowadays, things are much easier for us parents due to unlimited of resources on the Internet. Earlier this evening, after spending time learning with my grade 4 child about Least Common Multiple (LCM) [1], I wanted to know the quickest way to verify the answer when computing of some numbers....

Well, if you know you know, otherwise, you could have wasted the whole evening trying to upgrade RHEL 7.9 with High Availability to RHEL 8.x, and failed! If you read this post, head to the link at [1] and you’d see that Red Hat does not support i-place upgrades or rolling-upgrades of cluster nodes from one major release of RHEL to another. Here is an extract from [1]: Red Hat does not support in-place upgrades or rolling-upgrades of cluster nodes from one major release of RHEL to another....

So, what’s “Here Docs”? Well, if you don’t know what it is yet, then hopefully by the time you finish reading this post you’ll know what it is. Here docs or here documents is a special block code, of which we can use a form of I/O redirection to feed a command list to an interactive program, e.g. cat or the ex text editor according to [1]. Here is an example where a file basic-ingress....

On one of my servers, I used to have a storage device, /dev/sdb, attached to it. That storage was used as an LVM physical volume. It has later been removed, and now I just noticed the following message: [root@banan ~]# lvs Devices file PVID CuDRE3nMN5FMNqYLViHrnE1D7OFDlbX6 last seen on /dev/sdb not found. LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root almalinux -wi-ao---- <28.40g swap almalinux -wi-ao---- 2....