I have rendered my system unbootable. Help?

[redshirtsteve]

I have shot myself in the foot by getting cocky and editing my stab and rebooting. Now my MacBook Pro (ext4) will only boot to a command line with the fs in read-only mode.

I have my ext4 live usb stick, but cannot seem to figure out how to boot from it in this state. Can any assist?

TIA for any and all assistance!

[JerryF]

How did you boot from the USB originally to install?

[Mute Ant]

From the read-only command line, you can try...
sudo mount -o remount,rw /
...which often allows the waiting-in-the-wings Xorg to start.

[wallyUSA]

Hold down the Option key while you boot should give you the boot from USB option.

[prestonR]

First you'll need to either figure out how to boot your LiveUSB or work out how to edit fstab from the command line. Should be something like:

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cd /etc

to change to the 'etc' folder

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sudo leafpad fstab

where 'leafpad is your text editor
That should open fstab. Here you find the UUIDs of the boot, root and swap partitions that your system is expecting to find.

Now open a second terminal to check the real UUIDs of the partitions currently connected to your machine. Do:

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sudo blkid

to list all and try to identify the relevant partitions and if there are discrepancies go back to the terminal with your open fstab and correct the entry.

[Pierre]

if you insist on getting cocky and editing things like the /fstab
( don't be shy, we've all done something similar )
then - - always, always,, create a backup file - it's so easy to do, that you will think that you don't need to
- - File - Save As - OriginalFileName.bak ( I'll sometimes use *.org - - original )
and Then, only Then,, make the changes that you are testing out.

if worst, comes to worst,, then you boot into an Live Environment & change the filename, back again.
- and delete the faulty file, of course . .

[redshirtsteve]

I have linux-mint 18.3 installed on my MacBook Pro (2012.)

I have shot myself in the foot by getting cocky and editing my fstab and rebooting. I am pretty sure I removed the line to mount /.

Now my MacBook Pro (ext4) will only boot to a command line with the / fs in read-only mode.
I have my ext4 live usb stick, but cannot seem to figure out how to boot from it in this state. Can you assist? I am just looking to get a clean install of linux-mint 18.3 cinnamon back on this machine.

TIA for any and all assistance!

[WharfRat]

See if you can use sudo mount -o remount,rw / to remount it read/write then you can fix the fstab file with nano.

[all41]

I usually copy an fstab entry, place a # at the beginning of the line to comment it out,
then paste the copied line below it and make changes there.
This makes reversing the process or spotting entry errors easy.

[fabien85]

This is a duplicata of the following post: viewtopic.php?f=46&t=259325&p=1400193#p1400193
Maybe a moderator can merge the threads. Answers are given in both.

@redshirtsteve please make a single post about your problem next time

[Mute Ant]

You can boot a USB without any other drive attached, so whatever you did in /etc/fstab is, really, irrelevant to getting your machine to boot, if all you want to do is re-install Mint.

[Moem]

Mod note:
Topics merged. Please don't double post. Thanks!

[redshirtsteve]

See if you can use sudo mount -o remount,rw / to remount it read/write then you can fix the fstab file with nano.

Thank you so much!

I have gotten my install booted, and will attempt to figure out the next steps! Actually, any advice you may have regarding what those next steps might in fact be would be greatly appreciated!

Thanks again!

[fabien85]

The next step was given by prestonR above:
- use blkid to find out what your partitions are and their uuid
- edit the fstab as root to correct it: sudo nano /etc/fstab (ctrl+O to save the file, ctrl+X to quit)

For reference, the following are excerpts of my fstab, if you need example of the syntax and options

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# / 
UUID=blabla  /               ext4    errors=remount-ro  0       1
# EFI partition 
UUID=blabla   /boot/efi       vfat    noatime,utf8,fmask=0133,errors=remount-ro      0       1
# Swap
UUID=blabla  none  swap  defaults  0  0