Linux is my primary operating system. I used it on the servers, desktops, laptops, netbooks, and even mobile phones since approximately 1997. I’ve tried a number of distributions over the years, and even created a couple myself. I still look around sometimes to see what others are up to. But most of my machines are running some sort of Red Hat – either a quick and easy Fedora Linux, or a stable and secure Red Hat Enterprise Server, or a cheaper CentOS alternative.
And while by now I am very comfortable in the Linux environment (both graphical and command line), I still discover a lot of new and interesting things about it. When I come across something worthy, I usually share it with the rest of the Open Software world, using this category.
Red Hat is changing its logo from a “shadow man” in the red hat to just the red hat.
Not a huge change by any means, and I like it. It’s simpler and it’ll work better in black-and-white, as well as in smaller resolutions, like mobile screens and application icons.
Slashdot runs the story with more links and commentary, as usual.
aws-securitygroup-grapher is a handy tool that can generate a variety of graphs visualizing Amazon Security Groups. It is implemented as an Ansible role and uses GraphViz to produce the results.
This is particularly useful when you need to get familiar with a complex VPC setup by someone else, or when you want to review the results of an automated setup.
“Packets-per-second limits in EC2” is an interesting dive into network limits on the Amazon EC2. Even if you aren’t hitting any limits yet, this article provides plenty of useful information, including benchmarking tools and quick reference links for Enhanced Networking.
The conclusion of the article is:
By running these experiments, we determined that each EC2 instance type has a packet-per-second budget. Surprisingly, this budget goes toward the total of incoming and outgoing packets. Even more surprisingly, the same budget gets split between multiple network interfaces, with some additional performance penalty. This last result informs against using multiple network interfaces when tuning the system for higher networking performance.
The maximum budget for m5.metal and m5.24xlarge is 2.2M packets per second. Given that each HTTP transaction takes at least four packets, we can translate this to a maximum of 550k requests per second on the largest m5 instance with Enhanced Networking enabled.
Intermediate Vim is a nice collection of Vim tips and tricks, which are aimed at somebody who is already familiar with Vim. (There is of course no single definition of what’s advanced, intermediate or introductory, so we’ll leave that argument out.) But the article is well worth the read, even if you already know all of the mentioned commands. A refresher is always welcome.
Fedora 30 has been released a few days ago. In the long list of changes, the most interesting to me are:
I’ve already upgraded my laptop to this version and everything seems to work as expected. The upgrade from Fedora 29 to Fedora 30 is easy:
# Install all the latest updates
dnf upgrade --refresh
# Install DNF plugin for system upgrades
dnf install dnf-plugin-system-upgrade
# Download all the necessary packages for Fedora 30
dnf system-upgrade download --releasever=30
# Reboot and start the upgrade of packages
dnf system-upgrade reboot
# Cleanup after successful upgrade
dnf system-upgrade clean
If this is not your first upgrade on the machine, it might also be a good idea to cleanup some of the installed packages BEFORE the upgrade, so that the process goes faster, skipping unnecessary downloads and upgrades. Here are a few suggestions:
# List all installed RPMs by size
rpm -qa --queryformat '%{size} %{name}\n' | sort -rn | less
# List all packages from earlier Fedora releases
rpm -qa | grep -i fc28