RHEL6: Grub gives "Error 16: Inconsistent filesystem structure." after cloning an ext4 based /boot and /root

Solution Unverified - Updated 2024-08-07T04:57:57+00:00 -

Issue

Is there a problem cloning an ext4 /boot disk vs ext3 boot disk?
We have a process to copy our root disk setup to a backup drive for recovery. We do not want to use 'dd' to copy the whole disk because it is too slow.
The process includes the following steps:
1. Add a new disk to the existing system, a similar size as the existing system space (for /boot and /root).
2. Create a similar partition table on the new disk, so it matches the original disk as much as possible.
3. Create ext4 filesystems on the new disk partitions, matching the original disk.
4. Use 'rsync' to copy all files from the source disk filesystems to the new disk filesystems, using a command similar to the following:
```
# rsync /boot/* /mnt/clone_root/boot/ --sparse --delete --archive --hard-links --one-file-system
```
5. Use 'grub-install' to install boot loader on new /boot
When trying to boot the cloned disk with ext4 file systems we get the following error:

"Error 16: Inconsistent filesystem structure."

Replacing step #3 above with an ext3 filesystem on /boot does not produce the error, and the system can boot off the clone drive.
Note that the partitions created by the installer do not fall on a cylinder boundary. It is unknown whether this is related.

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