Bypassing Bad fstab Failure When Booting Linux

If /etc/fstab file is created with errors or the hardware configuration changes such as adding hard disks, Linux will boot into failure state. We can bypass the fstab failure by adding booting parameters to Linux. We can do this in two methods:

Method 1: Boot to single user mode 

When booting into single user mode, Linux will not mount anything. Then we can remount the / to some directory in read/write mode and then edit the /etc/fstab.
1. Boot Linux into single user mode
Press ESC in the grub menu and press ‘e’ to edit the grub entry. Add single to the kernel parameter like this:

kernel /vmlinuz-2.6.32.21-166.fc12.i686 ro root=/dev/mapper/VolGroup-LogVol00 vga=792 single

Then press ‘b’ to boot Linux.
2. Remount / in read/write mode

# mount -n -o remount,rw /

3. Edit /etc/fstab

Method 2: Add init=/bin/bash to kernel parameter 

1. Add rw init=/bin/bash

kernel /vmlinuz-2.6.32.21-166.fc12.i686 ro root=/dev/mapper/VolGroup-LogVol00 vga=792 rw init=/bin/bash 

to kernel parameter. Linux will boot and we will get a bash prompt. The / is mounted in read/write mode. We can then edit /etc/fstab file and reboot.

2. Remount / in read/write mode

# mount -n -o remount,rw /

3. Edit /etc/fstab