Unexplained HDD symbol
An unexplained HDD symbol sometimes appears to the right of a disk in the left-hand sidebar:
It doesn't seem to have any obvious reason, and doesn't seem to have a tooltip or anything attached.
See also https://askubuntu.com/questions/1226490/what-does-this-icon-in-disk-utility-mean
So this raises a couple of questions:
- I'm curious - what does it mean?
- Could there be a tooltip or some sort of explanation for it?
Thanks.