Switched from Catalina to BigSur and as normal this pops out when trying to upgrade macports:

You need to swich from bios to efi? Read on.
DISCLAIMER: you need to be familiar with these commands and make sure you have backup because you may destroy your linux if you do not pay attention.

1. List the existing partiton

# fdisk -l /dev/sda
Output:

I have recently switched to a retina Macbook pro and screen wise, some things are totally different there.
Like this situation where guest window of a virtualbox machine is so small that you cannot use it. So small than it is close to the preview thumbnail from VirtualBox manager.

So, you have a mac computer with touch id and you would like to use it also when you do "sudo su -" on Terminal but there is no menu to let you set up this.
You actually can, via Terminal :)
PS: there is one small downside. You need to do this after each OS upgrade. But since it doesn't happen so often and the procedure is very simple, I am ok with it.

You try to start your docker container with limits for memory and you get this warning:
Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.

At this point, I assume you have already cgroup working, CPU and RAM is limited and only swap is left.
These steps were done on Debian Buster.

Remember this article?
https://tar.gz.ro/linux-backup-restore.html

Linux is powerful and whatever linux based, is powerful too.
Cygwin can help you in many ways and in this article I will explain how easy is to clone an entire disk with it.
Proprietary and costly applications? HA! :)

!!! WARNING !!!
>>> DO THIS VERY CAREFUL BECAUSE WRONG CHOICES CAN DESTROY DATA <<<
!!! WARNING !!!

I can write tons of bla bla about block devices, UUID and all related but the internet (especially wikipedia) is full of this so I will let you do a search if you are more interested about any of this.
So, I will keep it simple: you arrived here because you need a fast way to see the UUIDs of your block devices (call them hdds, partitions, as you like).
There are various tools and commands to achieve that. Read on.

Some of us (like me) still have old macbooks that came with superdrive. Naturally, we have replaced it long time ago with a secondary disk.
Wondering what to do with the now apparent "useless" eject button?
Find below some useful key combinations.

control+eject

Shows a dialog box with following options:
go to sleep
restart
shut down.

command+option+eject

Goes straight to sleep.

control+command+eject

It restarts.

control+option+command+eject

Performs shutdown.

Some of you already know that Windows zip combines several different functionalities:
- compression (like gzip),
- archiving multiple files into one (like tar),
- encryption (like gpg),
- plus some other.

Unix and Unix-like operating systems tend to split them so do not be surprised to have gzip for compression, tar for archiving files into one and gpg to encrypt.