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

Jerry Geis wrote:

I have VMPlayer 12 running a CentOS 7 disk. Works fine.

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).

<snip>

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.

<snip> And the answer is that the mount handling is broken in 7, and I've filed a bug over a year ago. The workaround solution is to *not* put slashes in the LABEL; instead, do

e2label /dev/sda1 root

or, another filesystem, to use what we use, e2label /dev/sdb1 export1 which we mount as /export/1. Alternatively, mkfs.xfs -L /dev/sdb1 export1

mark