I have an external hard drive set up on a Mac mini that I’d like to access over the network. I thought it would be easiest to use AFP, but I ran into permissions problems, receiving errors such as “You may need to enter the name and password for an administrator on this computer to change the item named ‘foo’.” even though everything in question should have been owned by me. This only occurreed when trying to copy files over to the shared volume. After doing some googling and fiddling, I gave up on AFP. SMB (which is configured under “Options” in Sharing Preferences) ended up working fine.