Quick list:
Changing GRUB settings in Fedora
fstab mounts volume as read-only - solution for read-write
PHP with mysql support
Add linux user to a specified group
Unpack system stage tarball

Changing GRUB settings in Fedora

The main config file is in /etc/default/grub
After editing the file, the file (UEFI) /boot/grub2/grub.cfg must be rebuilt.
I would suggest making a copy of this file first.
cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg_backup
The do:
grub2-mkconfig -o /boot/grub2/grub.cfg


fstab mounts volume as read-only - solution for read-write

Edit your volume record in /etc/fstab
(assuming the partition uses ext4)
/path/to/volume/to/be/mounted /path/where/to/mount/it ext4 defaults,rw 0 0
The solution here is defaults,rw
Tip: Make a backup, or just copy and comment a line with # when modifying already-existing records


PHP with mysql support

If you compile php yourself, the default ./configure doesn't seem to have mysqli enabled.
If you try to connecto to a mysql server using your php, you will get an error

Solution:
enable mysqli at ./configure time.
./configure --with-mysqli --with-mysql-sock=/your/path/to/mysql.sock

optionally you can also specify where your MySql sock is (if it's not default)

Add linux user to a specified group

usermod -a -G group_name user_name

Unpack system stage tarball

This is based on Gentoo's handbook.
(https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Stage)
tar xpvf stage-tarball.tar.xz --xattrs-include='*.*' --numeric-owner

[Debian] Use Dedicated Nvidia card

After installing your Nvidia drivers, add this to your .bashrc:
export __NV_PRIME_RENDER_OFFLOAD=1;
export __GLX_VENDOR_LIBRARY_NAME=nvidia;

[Debian] Wine: could not load kernel32.dll, status c0000135 Kali Linux

Error: Wine: could not load kernel32.dll, status c0000135 Kali Linux
This happened to me after I installed wine32, after already using wine (normal 64bit version)
Solution: remove ~/.wine directory
(solution taken from https://unix.stackexchange.com/questions/728898/wine-could-not-load-kernel32-dll-status-c0000135-kali-linux)