Samsung Portable SSD T7 not working with Catalina

To whom may concern: in these case the fastest way is to zero some sectors (1-2%)of the disk via terminal and the all the options will reappear in Disk Utility.

BE CAREFUL: you might mistakenly erase your internal (or other important disk) if you do not pay the correct attention to the disk which has to be erased after reading the "diskutil list" command result.

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Samsung Portable SSD T7 not working with Catalina

I tried to connect a 1TB Samsung Portable SSD T7 to my MacBook Pro running under macOS Catalina, but failed to do so.

Starting DiskUtility, I noticed that the SSD is formatted as FAT32, that the disk cannot be partitioned, and that erasing/reformatting the disk as APFS is not available.

I also downloaded the T7 software from Samsung, but to no avail. The software simply claimed wrongly that the disk was not attached.

I wonder what I can do in this situation.

Also I would like to know which portable SSDs work with Catalina.

Strange you can't see it on the desktop (are the Finder prefs enabled in order to view hard disks?). After that the only way is to zero down some sectors via Terminal (1-2%) and Diks Utility will be able to format it in any way you desire. As I said above.

Secondly, any SSD MUST work with Catalina. There are no standards for Apple or for Windows in terms of hardware. At least in filesystems.

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

So I just got my Samsung T7. It was in FAT32 but ran the program on the disk. Which then had my computer restart. When it restarted, I went to the disk utility in Mac to erase and format . only Mac OS Journal wars available. No APFS. So I wanted to back up with Time Machine. I did that. And now it has one back up and is APFS. And it is in Read only. I cannot add anything to the external drive. I used to be able to have back ups and also some files on same external ssd.

Is this how it is supposed to be? Kinda pain in the butt....I want to be able to drag some files into the T7.

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!

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.

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.

Hi...Thanks for response...why not APFS ? ( versus MACOS Journaled )....My issue: I'm using Big Sur, Carbon Copy, Imac pro (2015 ) and Samsung T7. External drives not always showing up ( either from system preferences or holding down Option key on startup ).

I can get it to work usually by turning off MAC completely ( vs "restart" ) but the inconsistency make me uncomfortable and I don't have another MAC to validate the bootable clone with )

What I'm trying to achieve is cloning my MAC internal drive to the Samsung T7 , then restarting the Imac from the T7 to validate the clone actually works.

Thanks for any insights

The original poster had this as the last sentence . . . "Also I would like to know which portable SSDs work with Catalina."

Here's what has worked for me, and I have my 2017 iMac booting Catalina off of an external 250GB Samsung SSD, and a second external Samsung 1TB SSD that I use for backups and Macintosh HD clone via Carbon Copy Cloner.

While the Samsung T5 and T7 portable units can cost $149 and $169 respectively, you can pick up an "internal" Samsung SSD of 1TB for under $100 at Amazon or Best Buy. At Amazon, pick up this enclosure https://www.amazon.com/Sabrent-Tool-free-Enclosure-Optimized-EC-UASP/dp/B00OJ3UJ2S/ref=sr_1_3?dchild=1&keywords=ssd+enclosure&qid=1608258968&sr=8-3

and you're done. No additional software to install and the internal Samsung SSDs format easily within Apple's Disk Utility.

Been working for me perfectly! I also have a third Samsung 500GB set up this way to let me experiment with Big Sur without disturbing my working system.

Both Crucial (X8) and other vendors now produce 1GB/s performance external drives in enclosures with USB-C/A connectors. You are not the first to have issues with the Samsung T7 in the Apple Support Communities.

Hi. Working with the same problem but can't get anywhere since after installing the Samsung Portable SSD v.1.00 (from the SSD) my mac won't start (Catalina / MBP 2019). Have tried SHIFT and OPTION restart, but even the latter ends up stucked when the progress bar coming to an end. What next?

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...

Exactly what was the solution so you may help others with the same problem?

Look below:

The device you want to select will appear like you see selected in the above image. The drive name may be different on your machine.