Samsung Portable SSD T7 not working with Catalina

In Disk Utility, type CMD-2 (aka in View Menu, SHOW ALL DEVICES)

Then Select your SSD DEVICE (not Volume)

Now the Erase drop down will allow APFS and the Partition button will be enabled

Format the drive HFS+. If that works OK, then use Disk Utility to convert it to APFS. Be sure you have set the Partition Scheme to GUID.

You need to go through some hoops when working with non-Mac formatted drives. This may be especially problematic if the new drive is formatted using NTFS to which macOS cannot write.

Sorry, it. won't let me edit my original response ... the above instructions by Fuchs DO work, with the new PSSD software, IF you (and this is probably obvious to everyone but me) set the disk utility view option to show all devices (facepalms), Disk Utility > View>"show all device".

No worries, I had this problem too and its an easy fix.

1. Open disk utility and select the drives top extension. Mine was labeled Samsung PSSD T7 Media.
2. Click "Erase" and when the pop up opens, rename your drive if desired, change the format to APFS, and the Scheme to GUID partition map, and then click erase.
3. Now the "Partition" icon will light up and you can partition the drive.

Good luck!

I followed all the steps in this post, used the Samsung software to unlock / turn off the security features of the drive, but the Partition button was still grayed out for me.

Ultimately what worked was a comment at the end of the post that suggested using Time Machine to re-format the disk first, and then I could use the Partition button.

Maybe just re-formatting it first as HFS-Extended would also then allow access to Partition. I was trying to get from Fat-32 straight to APFS but maybe that is not possible in one step.

Now I have to uninstall all the Samsung Kernal extension garbage...

Make sure you are formatting at the device level.

I recently obtained a 1 TB SSD T5 Samsung and a 2 TB SSD T7 Samsung, both external SSDs. They came formatted as Master Boot Record. I am running Catalina. I opened Disk Utility and selected Erase at the device (highest) level, selected GUID and APFS (all in one step, for the erase), and both are now APFS. I have used these to make bootable "clones" of my computer, running Catalina. The speed of the devices is extraordinary: the T5 reached 500 MB/s, and the T7 was close to 900 MB/s. The clone of my entire computer just took several minutes.

I suspect that the individual having trouble reformatting a T7 was sent a unit that was misconfigured by Samsung, leading to difficulties.

Detach any external mass storage you don’t need.

from Terminal: diskutil list

Let’s suppose your t7 is unit /dev/disk2

from terminal: diskutil zerodisk disk2

until it get’s to 2-3%.

stop operation - ctrl-z

exit Terminal

go to Disk Utility and format it as you like (normally APFS)

PLEASE NOTE: this is an extremely riskful operation!!! Be sure you are going to erase the correct volume as there is a possibility to erase you’re internal hd by mistake!!!

be sure sure to have a backup if your startup disk in order to perform a restore in case of mistake.

BE VERY CAREFUL!

That worked for me, however, in step 2 I had to change the Scheme to GUID partition map first before APFS would appear as a format option.

Thanks!

My problem was that the drive was formatted to fat 32 I used EaseUs data recovery program -$89 ( after paying $50 for another program that didn’t work as well) , recovered my data then reformatted to MacOS Journaled. During all that I was harassed on this forum for trying to get help. So My process worked for me! I learned more about proper formatting and the importance of more than one backup of your files.

There was no input from Samsung. I remember getting frustrated that Disk Utility was not allowing for partitioning. So I let time machine do the work for me. Then I used Disk Utility successfully. In my case, that meant portioning half the drive for backup and half for general use.

DO NOT PERFOM THE FOLLOWING WITHOUT A BACKUP OF YOUR MAIN DISK!!!

1) Detach any/all disks from your mac except for the external SSD

2) From Terminal: diskutil list

Post screenshot of the result here.

Simon

Ok . I figured out what I did wrong. I was overthinking this whole think. I just needed to partition off the external drive. I did that and now when I plug in the T7 , two drives pop up. the readable only with back ups and Personal where I can store the files.