I just setup a new server with a minimal installation of AlmaLinux 8. AlmaLinux is a variant of free Red Hat Enterprise Linux 8. It’s like a CentOS 8, but will have a full support until the end of RHEL 8 life cycle. This server is to serve as a new proxy for all VMs inside my home lab. I want to use tinyproxy which is need to be compiled from source as the RPM package is not available as of the time writing. After downloading the source code, and try to decompress it, I was presented with the following error message: ...

Recently, I found out that the ZFS pool on a FreeBSD is running out of space. There is no option to clean up this storage, but there are spare disks. So the next logical thing to do is to add 2 extra disks to the existing (mirror) ZFS pool. This FreeBSD server is a virtual machine (VM), and after attaching 2 physical disks to this VM, I had difficulty identifying these disks. Well, I could guess it, but this is a production server, and I really don’t want to spend my whole weekend to setup this server from the backup. :) ...

I have a Void linux VM which only gets turned on once in every month. Today, when I booted up and updated the packages on this VM, I noticed that there are many old kernels installed. As a seasonal Void user, I had no clue on how to remove older kernels. Fortunately, a quick Google search pointed me to a video: VOID Linux: Removing old kernels with vkpurge. Basically, Void comes with a pre-installed utility program called vkpurge. (man vkpurge for more info.) ...

If you’re familiar with Kerberos, one way to check if a ticket is valid is to run klist command. ❯ klist Ticket cache: FILE:/tmp/krb5cc_1001 Default principal: username@UNIVERSITY.EDU.AU Valid starting Expires Service principal 02/07/21 11:26:50 02/07/21 21:26:50 krbtgt/UNIVERSITY.EDU.AU@UNIVERSITY.EDU.AU renew until 03/07/21 11:26:50 02/07/21 12:24:07 02/07/21 21:26:50 cifs/server1.UNIVERSITY.edu.au@UNIVERSITY.EDU.AU 02/07/21 12:24:07 02/07/21 21:26:50 cifs/server1.UNIVERSITY.edu.au@UNIVERSITY.EDU.AU ❯ date Mon 05 Jul 2021 16:01:59 AEST From the above output, the principal ticket expired since 2 Jul. So how do we find out if the Kerberos (principal) ticket expires programmatically? This is something that I was trying to find out a few years ago, but kinda have been forgotten due to low priority. ...

Suppose you just connect a Raspberry Pi to your home network using ethernet interface, and the Pi is not connected to a display device. How would you find an IP of that Raspberry Pi? Well, you’re right…whatever you say. There are a few ways to do this - looking at DHCP log, router log, …etc. But here is an even easier way to achieve this - using a command line tool called nmap. ...