APFS option not appearing in DISK Utility

I struggled with a similar issue as I needed to convert to APFS for Catalina upgrade. Via Restart Cmd-R I was trying to use the older disk utility that was installed (I think the version was from 2016). It didn't have APFS as an option. What finally worked is I did Restart Cmd-Opt-R to get the "online" Disk Utility (2019 version). This allowed me to erase the drive using APFS. Catalina is currently being installed.

You need to erase the device, not the volume. The device needs a GUID partition map for APFS.

junirpilot wrote:

If I want APFS erase in Disk Utility, what to do if the partition map is "Master Boot Record?" This is on a newly purchased LaCie 2TB SSD External Rugged Mini.

Set the device to partition map GUID and then format as APFS (case insensitive).

junirpilot wrote:

Thank you Matti Haveri. But there's a problem for me. When the device is chosen, The "Partition" icon in the top menu bar of the Disk Utility is greyed out and won't do anything. I know of no other way to change the partition map.

That's not required anymore. Click Erase with the device selected and you can change the partition map.

Shailjasheetal -

Further ... just to be completely explicit ... the device is your "Samsung PSSD T7 Media" ... not the "T7" volume.

Thank you Matti Haveri. But there's a problem for me. When the device is chosen, The "Partition" icon in the top menu bar of the Disk Utility is greyed out and won't do anything. I know of no other way to change the partition map.

If I want APFS erase in Disk Utility, what to do if the partition map is "Master Boot Record?" This is on a newly purchased LaCie 2TB SSD External Rugged Mini.

Thank you Barney-15E. It worked and now I can proceed.