Create additional partition on Time Machine external drive?

I'm not entirely sure that you can do this. My experience has always been that what you want is an all or nothing process.

 

I'm not 100% sure you can do that. Whenever you partition a drive (in my experience), disk utility will wipe everything clean to re-partition it. You could create a new disk image on the hard drive, but you may be limited to a smaller amount of space than you are looking for. =/

 

???

Yes you can add a new partition to an existing drive in Disk Utility - just select the top level of the external drive in Disk Utility, click on the Partition tab and then the "+" below the drive. It should create a partition out of the free space and you can decrease the size by moving the slider. Set options and rename. Should not be a problem.....

However there is no need to create a new partition unless you particularly want to - you can save your files to the external Time Machine drive same as a normal external drive. Time Machine won't mind and if you take up too much space with these other files it will warn you before it starts overwriting old backups..