I have a large VirtualBox VM on an external HDD. The HDD fails the S.M.A.R.T. test. The VM still works fine, but any regular attempt to copy the VM files over to a healthy drive fails ... there is clearly already something corrupt in the VM's virtual HDD, although it is not (apparently? yet?) affecting the functionality of the actual VM.

Any suggestions on how to save the VM? Linux Mint Guest OS, Pop_OS (Ubuntu) Host. The VM is nearly 800 GB. Both regular copy and rsync fail.

Thanks,
Eric

PS: (and perhaps I should have led with this, but...) is it okay to ask these kinds of specific, technical, "help me with my tech-stuff" questions here on Tildes?

Update to the update ... moved update info into a comment ... will keep my progress updated in that primary comment.

Danke, y gracias to all