user@debian:~$ journalctl -xe | grep "mount: /dev/sda1 already mounted or mount point busy"

Critical

mount: /dev/sda1 already mounted or mount point busy_ (Debian)

mount: /dev/sda1 already mounted or mount point busy

Debian · Boot/GRUB

When Debian throws mount: /dev/sda1 already mounted or mount point busy, the system diagnostics have flagged a condition known as "mount: /dev/sda1 already mounted or mount point busy". Most fixes for this error are straightforward and don't require wiping your drive.

What Actually Happened

System boot halted: the target mount point conflicts with an already active mount.

Symptoms

Linux boot halted with message: 'mount: /dev/sda1 already mounted or mount point busy'

Common Causes

Boot condition: the target mount point conflicts with an already active mount

How to Fix It

01
Boot from a Live USB media
02
Chroot into installation and run:
sudo update-grub
03
Reinstall bootloader:
sudo grub-install /dev/sda

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