I have bought a 1TB SanDisk Extreme Portable SSD (external) drive for my MBP (Mojave).
When I erase using Disk Utility I am not offered APFS (not sure why?) and format as Mac OS Extended (Journaled).
However, I can not partition the drive into 2 x 500GB but the Partition button is greyed out. Is it not possible to partition??
I did, but only read after I had formatted ☺️
I found that if I partioned the drive as Mac OS Extended I could create a partition that would format AFPS. I have one for Time Machine (Mac OS Extended ) and one for a SuperDuper backup (AFPS).
This is a short-term backup for a my wife's 6 year old MacBook Air (SSD failing error). I already have a separate (second) Time Machine backup on a Mac Pro. She is travelling so I am setting this up for her so that she can do a SuperDuper backup at the end of each day and also have a Time Machine backup. All her working documents are in the cloud. New MacBook Air on order!
Thanks for responding, much appreciated.
Change the View at the top left to "Show All Devices".
When you formatted the drive, did you choose GUID as the scheme?
You're welcome. If you're formatting drives for Macs you should use GUID.
Also found this for anyone else encountering same issue:
Disk Utility for macOS Sierra: Partition a physical disk using Disk Utility
One final question, assume i should be formatting APFS (option now available!)?
Not if you are going to use the drive for Time Machine. There is a slight advantage to format SSDs as APFS. I haven't bothered yet. Just because APFS is relatively new.
I formatted the two partitions as APFS and noticed that they are not available for Time Machine (not visible when you select disk in TM) . Do I need to format one partition as Mac OS Extended to make it visible to Time Machine?
Did you notice what I said?
"Not if you are going to use the drive for Time Machine". 😎
Personally I would not partition a drive for data and Time Machine. If (and when) the drive fails, you will lose both your data and your backups.
When I select erase these are the only options I get?
Thanks. learnt something new!
What do the different schemes do and which one should I select?
One final question, assume i should be formatting APFS (option now available!)?
That's slightly out of date because it doesn't include APFS information. For what it covers it's correct.
Hmm, I noticed that only APFS is available to me when I try to format. I guess I have to format the whole drive as Mac OS Extended if I want to use for TM.
You're welcome. Enjoy the new MacBook Air.
How to partition an external SSD Drive?
