virtualbox.org

Not sure if this is by design but any suggestions on how to address this I would appreciate.

I noticed my backup system was not making more recent backups of my VDI files. I looked at the VDI file itself and it shows a last modified date of a month ago. I have definitely written data to the virtual hard drive since then. I have also restarted the virtual machine (And the physical host server) several times since then. But still the date modified remains a month old (The original creation date I believe).

Any thoughts on how to force VirtualBox to update the modified date on these files so they are included in incremental backups?

Wild guess: you are using snapshots, which indeed means that the base disk is frozen. Short of a monstrous bug in the host OS, this is the only explanation I can think of. Certainly no VirtualBox bug can prevent the host managing timestamps on its files.

I had a feeling once someone answered my question I would be slapping myself in the head and saying DUH

Thanks! I am using snapshots