@DHS Thank you for letting me know. I will make sure the external drive I use for transferring files is HFS+ then. As long as Linux is able to read the files I transfer over that is enough for me; document files and music files especially. For the document files, I will make sure they are compatible with the Linux applications.
Thank you everyone for your help.
I will definitely need to learn how to make and automate backups for my Purism computer hard drive.