[CentOS] VM disk question

> However I wish to change the disk from UUID booting (fstab) to the old
> style LABEL.
> (so I can export it and use on another machine).
>
> however when I run:
> e2label /dev/sda1 /
> e2label: Bad magic number in super-block while trying to open /dev/sda1
> Couldn't find valid filesystem superblock.
>
> Three questions:
> 1) Am I doing something wrong?
> 2) Is there a better way?
> 3) How do I support VM formats (VBox, VHD and VMWare) easily?

Is this an xfs filesystem or an ext4 filesystem? I could be wrong, but I 
suspect that e2label would only work on an ext2/3/4 filesystem. The 
default filesystem in RHEL/CentOS 7 is xfs. It looks like you can check 
labels on xfs filesystems with

xfs_admin -l </path/to/filesystem>

and you can set a label on an xfs filesystem with

xfs_admin -L "<your label>" </path/to/filesystem>

If you run "blkid" on your system it will give you all labels for all 
disks connected to your machine for any filesystem types that it understands.

I don't think this has anything to do with physical or virtual disks or 
virtual disk formats either. Here we are just talking abut filesystems.

Hope this helps.

Barry