I'm sure this is a question that has been asked many times, though I couldn't find a reply that put my mind completely to rest. Sorry if it seems trivial or blindingly obvious. I have found myself going round in circles in my research and would appreciate someone's advice! I am partitioning a new external hard drive for use with: 1) Time Machine 2) Media storage and 3)A Carbon Copy Cloner (or perhaps SuperDuper!) clone of my 128GB internal SSD. Of this 128GB (actually 121GB, according to Disk Utility), I'm currently using about 55GB, so intend to allow 250GB for Time Machine Backups. I am aware that one is unable to resize the final partition of a drive using Disk Utility, so intend for the clone to reside here - since its maximum size (128GB) is fixed. Thus, I will have approximately 620GB remaining for general media storage. My partition scheme would then be as follows: 250GB Time Machine 620GB Storage 128GB Clone Do you think 250GB will be adequate for Time Machine in my situation? Will it be possible to enlarge the Time Machine partition (the first partition on the drive) in the future, if ever required? I would rather make the second (storage) partition as large as possible for now, than allow Time Machine a lot of extra space which may well go unused. (My current TM drive has a 500GB partition with only 56GB used.) My understanding is that this would not possible without erasing the second partition. Am I correct? TL;DR: Is it possible to enlarge a disk partition without erasing the partition below it? Many thanks in advance.