I hope I have posted in the correct forum. I had a choice between:
* Linux - Newbie (I'm not even though I didn't know the e2fsck command)
* VirtualBox (not exactly this problem), or
* CentOS which I am trying to load up via VirtualBox
I have tried Googling which lead me to forum sites like this but not had any success and importantly was too afraid to try more in case it causes more issues. Any help would be appreciated.

Here is what I can see when I tried loading up. I did not do anything like mount or didn't shutdown properly like what other people mentioned they were doing. I have included more info following this error message.


Starting udev: [OK]
Setting hostname localhost.localdomain: [OK]
Checking filesystems
fsck.ext4: No such file or directory while trying to open /dev/mapper/VolGroup-lv_root
/dev/mapper/VolGroup-lv_root:
The superblock could not be read or does not describe a correct ext2
filesystem. If the device is valid and it really contains an ext2
filesystem (and not swap or ufs or something else), then the superblock
is corrupt, and you might try running e2fsck with an alternative superblock:
e2fsck -b 8193 <device>
[FAILED]
*** An error occurred during the file system check.
*** Dropping you into shell; the system will reboot
*** when you leave the shell.
*** Warning -- SELinux is active
*** Disabling security enforcement for system recovery
*** Run 'setenforce 1' to reenable.
Give root password for maintenance
(or type Control D to continue)



Here is further info
* /etc/fstab
https://drive.google.com/open?id=1iO...oiId-BdZo5zE-e
* fdisk -l
https://drive.google.com/open?id=13h...02fPcE0k43sZlD

Your /etc/fstab and fdisk -l output didn't seem to correctly attach to your post. Could you either edit your post or post those in response to this thread?

Something has corrupted the Linux LVM volume structure in that VirtualBox container, or perhaps just changed its UUID such that the CentOS initscript cannot find it.

What did you do to see the /etc/fstab listing to which you attempted to post a link? That would help explain what might have happened to that volume.

(Corrected image links below.)

wagscat123, for completeness i removed the "[IMG]..[/IMG]" tags from my original post. Appreciate your viewpoint.

@rknichols, thanks for giving the image links. Re: what i did differently to cause this, i recall having only used a different computer from the one at school. Having said that, i don't understand why the error refer to ext2 when the fstab mentioned ext4 and i did not change the fstab. By the way, i don't know how to change the fstab anyway even if this is the solution nor i know what UUID to change to - should i try changing the Machine, HardDisk and Image uuid values in .vbox file as suggested in https://stackoverflow.com/questions/...a-virtual-disk ? Isn't that a forceful way to do rather find the UUID from the GUI and change it in the fstab? Otherwise, I may try to use the same computer when school resume.

ext2/3/4 are the same basic filesystem with features added at each version. They all use the same filesystem driver. It's actually common for the driver try ext2/3/4 in sequence and stop when no more incompatible feature flags are found in the super block. You aren't getting that far, since LVM can't locate (or at least hasn't activated) the volume that contains the filesystem. It's like missing /dev/sda1 and then seeing a message that "fsck /dev/sda1" is failing.

I'm afraid I domn't know enough about VirtualBox to comment on that procedure. With a similar problem elsewhere, my preference would be to boot from a rescue CD and use the lsblk command to see the UUIDs, and determine what is different from the UUID for which the boot loader is looking.

If you can get the VM to boot to a Live ISO image or into its Linux installation at all, you definitely can use lsblk or blkid, and edit your fstab file to get things working again

Maybe. It appears that the volume with the root filesystem isn't being found, so the contents of /etc/fstab are not relevant.

This sounds more like an issue between the boot loader and the structure or labeling of the root LVM volume.