Work related -- a quick reference --

sudo apt install ubuntu-desktop

Disable update notifier

sudo apt-get remove update-notifier

Edit

emacs .config/gtk-3.0/bookmarks

mdadm –stop /dev/md0
mdadm: Cannot get exclusive access to /dev/md0:Perhaps a running process, mounted filesystem or active volume group?

ls /dev/mapper/
dmsetup remove /dev/mapper/vg0-swp

Now you can stop the array

mdadm –stop –scan

cat /proc/mdstat

root@ubuntu:~# cat /proc/mdstat
Personalities : [raid1]
unused devices:

Now clean disks

lsblk

sda      8:0    0 111.8G  0 disk
??sda2   8:2    0 111.3G  0 part
sdb      8:16   0 111.8G  0 disk
??sdb2   8:18   0 111.3G  0 part

 sgdisk --zap-all /dev/sda

Enable the rpmfusion repo. Download it from https://rpmfusion.org/Configuration

wget https://mirrors.rpmfusion.org/free/el/rpmfusion-free-release-8.noarch.rpm
rpm -i rpmfusion-free-release-8.noarch.rpm
yum install fuse-exfat
mkdir /media/usb
mount /dev/sdx /media/usb #Where x is your device name i.e sdd1