Mixed permissions on backup drive
I use a USB hard drive to store all my backups. All files and directories on this drive are owned/grouped by my user, except one directory which I use to store partition image files created with the program Partimage. These gzip files are created as root and must remain that way if they ever need to be used (ie. to restore a partition). The directory they live in is also owner/group root. Non-root access is read-only on this directory.
My question is, can problems arise if a directory owned by root resides on a partition in which all other files/directories are owned by user, and which is normally mounted by user (I only mount this partition as root when creating/deleting image files)?
The problem I'm thinking of is root taking ownership of files normally owned by user. No programs are run from this drive but is it still a potential problem, say, when root mounts the drive?
I used to have the image files on their own partition on this drive, but found it cumbersome and a waste of disk space, so I'd prefer not to go back to that.
Thanks in advance.