If you are currently using CentOS 8, you will have to find an alternative operating system. This is because its end-of-life cycle has been cut short in December 2021. But if you use CentOS 7, you do not have to take any action right now. This is because CentOS 7 will reach its End-of-Life on June 30th, 2024.
Source: CentOS Replacements For Your Production Linux Servers
Stupid me installed CentOS 8 in December 2020 instead of 7 without reading the news about this.
While it is somewhat understandable that Red Hat may not want to support a free enterprise-grade Linux OS forever, there was a real sting in Red Hat’s announcement last year, as it leaves CentOS 8 users in a tough spot, needing to secure their CentOS 8 workloads rapidly.
Source: Moving Forward After CentOS 8 EOL
The end of CentOS 8 Linux has been coming for awhile now, and the day is finally here. On December 31, 2021, Red Hat‘s CentOS Linux 8 will reach End Of Life (EOL). Since that falls right in the heart of the holiday season, Red Hat will extend CentOS Linux 8 zero-day support until January 31, 2022. Indeed, there will be one last CentOS Linux 8 release — perhaps even after CentOS 8’s official EOL. After that, it’s all over for CentOS Linux.
Source: CentOS Linux 8 is about to die. What do you do next? | ZDNet
Yikes! Just heard about this. Last year I chose CentOS 8 over 7 for this server so I would not have to deal with end of life issues for awhile. It appears CentOS 7 will be good until 2024 and 8 ends today. Ugh.
You can run Pi-hole in a container, or deploy it directly to a supported operating system via our automated installer.
Source: Pi-hole®: A black hole for Internet advertisements – A black hole for Internet advertisements
What’s more interesting is that this flaw can be exploited by an attacker to run commands as root just by specifying the user ID “-1” or “4294967295.”
That’s because the function which converts user id into its username incorrectly treats -1, or its unsigned equivalent 4294967295, as 0, which is always the user ID of root user..
Source: Sudo Flaw Lets Linux Users Run Commands As Root Even When They’re Restricted
Dennis MacAlistair Ritchie’s was “dmac”, Bourne’s was “bourne”, Schmidt’s was “wendy!!!” (his wife’s name), Feldman’s was “axlotl”, and Kernighan’s was “/.,/.,”.
Source: Computer historians crack passwords of Unix’s early pioneers / Boing Boing
and Ken Thompson’s was “p/q2-q4!” (chess notation for a common opening move).
CentOS offers a bit of a different take on installing and updating packages. First off, the default package manager has migrated from YUM to DNF. The command structure for each is quite similar, so instead of running a command like:
sudo yum install httpd
You’d issue the command:
sudo dnf install httpd
For more information on DNF, see How to use the DNF package manager.
Source: CentOS 8 is finally here – TechRepublic
As you’ve probably seen in the comments to your question, the cronjobs in
/etc/cron.hourly (and the other, similar directories) are executed by
run-parts is a little picky about filenames. By default it doesn’t execute files whose filenames contain anything other than (all of those from ASCII)
- uppercase letters
- lowercase letters
- dashes (“minus signs”)
So if your script has a filename of for example “myscript.sh”, it just is ignored, because
run-parts does not like the dot.
Source: Why putting a script in /etc/cron.hourly is not working? – Ask Ubuntu
In this tutorial, we will see how to use the terminal to clean up unused memory that was not released properly after being used by your system. No need to use any third-party software, just a few commands will do the job pretty easily.
Source: How to Free up Unused Memory in Ubuntu/Linux Mint
Have a little problem with a server freezing which might be memory related. This simple tutorial was very helpful.
You can free up unused memory under Ubuntu/Linux Mint using this command:
sudo sysctl -w vm.drop_caches=3