How to recover from an "umount -a -l"

Question

So I did this silly thing:

umount -a -l

And had nothing in my fstab so couldn’t do mount -a

So I thought: “It will be ok when restart” … But no.

Now I'm stuck at launch and I don't have anything to logon just and error telling me to contact administrator

I'm using Kali Linux.

EDIT:

I can log by pressing ctrl+alt+F2 (it opens a shell)

before I did this umount I did this command:

dd if=/dev/zero of=/mnt/sdb2

So apparently it was a bad idea

Now df -h says that / is full and I got both 'rootfs' and '/dev/disk/by-uuid/' mounted on / (and full).

But the strange thing is that du -sch / tells me 9.5G and my disk capacity is 20Go.

I also did the following things:

• Change my fstab and remove UUID lines by more 'usual' lines and reboot : did nothing at all.
• Ran fsck.ext4 /dev/sda6 says 'clean'
• Ran upgrade-grub just in case

I don't know what to do anymore :|

Answer 1

After Booting live, I mounted my partition /dev/sda6

mount /deV/sda6 /mnt/

then I saw with du a 9.0G file called /mnt/dev/sda.

head /mnt/dev/sda | cat -e revealed that it was full of ^@ which is null in caret notation

This file was the result of my fail.

In fact when I ran dd if=/dev/zero of=/mnt/sdb2 I did something wrong (mistype, of=/dev/sda, ...) and filled my disk with zeros

after removing this file everything was ok since disk was not full.