I've got an external networked HD. One of the partitions on it is for achiving. It will be used by both macs which are on the network. What I've done is create a folder on it to be used by the other mac. This folder will naturally keep growing. I thought of doing this and I was wondering if it is a waste of time or if it is actually a good idea with regards to help keeping the external disk optimised. Instead of having a continually growing folder for the other mac to use I thought of creating a 20 gigabyte disk image on it instead. Is there any point in doing this?