i made a change to the
/etc/fstab that looked perfectly fine until I rebooted the system (CentOS 6) running as a virtual machine. The system did not start, there was a Kernel panic, and using the single boot mode did not provide any access to the system. I changed the
"/" partition to a UUID number after changing the volume name. By any account, I am still not clear why this failed, the syntax looks sound. This is something I have done in the past.
Anyway, I could have given up here and reinstalled the OS since this was a fresh build, but I wanted this to be a teachable moment. Fortunately, this was time well spent.
These are the steps i took to resolve this.
- Download the CentOS-6.5-x86_64-LiveCD.iso.
- Mount the ISO to the system
- Reboot the system to the ISO
- Open a terminal window
Once here I wasn't exactly clear what to do next, since
fdisk clearly sees the hard drives, but these are logical volumes. I will need to mount a logical volume.
vgscan(use this to list the volume groups, look for the volume that needs to be mounted)
vgchange -a y(activate all available volume groups)
lvscan(scan for logical volumes, and displays that the devices are now active)
mount /dev/my_vg/my_lv /mnt
vim /etc/fstab(correct the offending lines)
vgscan vgchange -a y lvscan mount /dev/my_vg/my_lv mnt vim /etc/fstab reboot
Upon reboot, the system came back up as expected!