SSD shows in System Info but not DiskUtil

Question

SSD shows in System Info but not DiskUtil

I have a late 2015 iMac running Monterey. The main 2TB fusion drive recently got flaky and I had to reinstall the OS. I decided to make an external boot drive using a Crucial X6SE 2TB SSD. It showed up in System Information but not in Finder or DiskUtility. So I returned the SSD and bought a Samsung T7. Same thing. It shows up in system information but not in the Disk Utility of Finder. I have used the cables supplied by the drive manufacturer--the Crucial had a C to C with an A to C converter. The T7 has a cable which goes USB C to USB A. For the crucial, I even used my own C to A cable. No luck. I have tried all ports. No luck. The other USB ports work because I have a wireless keyboard dongle in one and had an external HD attached at one point for Time Machine. I took the Crucial drive and formatted it for GUID partition table using APFS on my MBP without issue but it wasn't seen by my late 2015 iMac. The T7 drive is ex-FAT and I didn't bother formatting for APFS. Is invisible to Disk Utility and Finder but visible under System Information. Any ideas?

--John

Posted on Oct 16, 2023 2:13 PM

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Answer 1

Top-ranking reply

JohnJohnsonIII Author

Level 1

4 points

Oct 20, 2023 6:02 PM in response to JohnJohnsonIII

So here is the answer:

The reason I could not see the drive is that the system could only see Mac OS Extended(journaled) formats. All explanations I saw mentioned you need to install APFS, but that format is not compatible with the older OSes. So at length I figured it out because an old backup disk I had was visible yet other regular external disks(HD or SSD) were not. The diff was the formatting. I have installed as Mac OS Extended and it is readable and is now my boot drive.

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Answer 2

ku4hx

Level 7

23,610 points

Oct 19, 2023 12:01 AM in response to JohnJohnsonIII

If you wish to wipe the drive as opposed to reinstalling the OS, this is what you do: Create a bootable installer for macOS - Apple Support

Br sure to understand the procedure first, read it fully and do exactly as directed for your Mac. Backup, backup, backup ...

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Answer 3

tbirdvet

Level 6

14,711 points

Oct 16, 2023 4:15 PM in response to JohnJohnsonIII

In Finder do you have it set to show connected (external) drives in Finder settings menu? Also in Disk Utility you need to check off "show all" or the drive will not be visible under the view in the panel header menu.

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Answer 4

ku4hx

Level 7

23,610 points

Oct 17, 2023 4:31 AM in response to JohnJohnsonIII

My wife had that exact model and at one point had your same problem. The fix for her machine was to reinstall the OS. That was in late 2020 so the OS was whatever was the latest at that time.

After that, all external drives showed up as expected including a trio of Samsung T7s.

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Answer 5

Oct 18, 2023 10:16 PM in response to ku4hx

I agree. Last night I tried to use disk utility to wipe main drive from Recovery but couldn't see it. So I used an Ubuntu stick to boot and wipe drive. I did this before, but this time when I start into Recovery it can't see the internal hard disk. Nor can it see any external SSD. I have tried a Crucial X6, Samsung T7, Sandisk 1TB, and now the Apple-approved LaCie from the Apple Store. NONE of them are visible. Used all the USB ports, different cables. Before when I had access to the OS I could see the external SSD in System Info but not Finder or Disk Utility. Finder preferences were set properly.

For SOME reason it won't see any external SSDs or the internal fusion drive.

It WILL see external hard disks, just not SSDs...

Anyone know why it can be seen by system info but not disk utility?

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Answer 6

Oct 19, 2023 1:21 AM in response to ku4hx

I don’t care about the internal drive one way or another. I simply want to install an OS on an external SSD for booting the computer since the HD is not trustworthy. I can’t make a bootable thumb drive because you can’t install older OSes on it. I have a MacBook Pro but it has Ventura and won’t download the other OSes from the store. If I try to use internet recovery on my 2015 iMac it sometimes offers El Capitan or Monterey or Mojave. 2015 can only take up to Monterey. The problem is the HD isn’t visible nor are any external SSDs but external usb hard disks are visible.

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