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2018 Mac mini won't boot off Sandisk Extreme SSD

Duncan68

Duncan68

macrumors 6502a
Original poster
Sep 22, 2018
508
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I bought a 500GB Sandisk Extreme SSD in order to back up my mini's internal boot drive using Carbon Copy Cloner. The mini refuses to boot from this external SSD. The progress bar gets almost all the way across and then the mini shuts down. I have the setting in Startup Security Manger to allow external booting. I tried the troubleshooting steps that Bombich Software offers in this document:

Help! My clone won't boot! | Bombich Software

bombich.com bombich.com

Nothing worked. I did try the drive hooked up directly to a Thunderbolt 3 port on the mini and also hooked up to a USB hub (which was connected to a Thunderbolt port).

I'm out of ideas. My question is, what value does this drive have for making non-bootable backups of my internal drive? I don't have a second Mac I could use to re-image the internal drive (should it get corrupted) with the backup. As far as I know, there is no stand-alone boot program for Mac to image drives like Acronis offers for Windows PCs.

Since the Sandisk drive now has a copy of my internal drive, I am reluctant to return it, as I don't really trust any wiping/formatting I could do to it.

Any thoughts would be welcome.
 
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It should have booted. My Samsung T5 SSD with USB-C boots my iMac from the TB 3 port. That's with a CCC clone of Mojave. If you've tried everything, it could be the Sandisk is not compatible. Wipe it and return it. Use security wiping by overwriting it 3X.
 
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If the connecting cable is removable -- have you tried a DIFFERENT cable?
Do you have access to another Mac? If so, do you get the same problem on the other Mac?

Another approach you could try:
- Download a new copy of the Mojave installer from the app store and put it into your applications folder
- Use disk utility to erase the Sandisk SSD to Mac OS extended with journaling enabled, GUID partition format.
- Launch the OS installer, and install a brand-new copy of Mojave onto the Sandisk SSD
- Does the install "go through"? If so, you should see the setup screen.
- Begin setup, and at the appropriate time choose to "migrate" all your stuff over to the new drive.

I realize this involves some work, but if the Sandisk still won't boot after doing that, I'm thinking that -something- inside of it (probably in the controller board) doesn't support booting on the Mac OS.
 
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I am on MacBook and use CCC to boot from Samsung T5 connected via USB-C dock and using USB-A to -C.

PS: there are always lots of user tracking info in URLs. Everything from "ref=" on is just not needed. The "dp/xxxxxxx" is the item/part you need.
 
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Duncan68 said:
I bought a 500GB Sandisk Extreme SSD in order to back up my mini's internal boot drive using Carbon Copy Cloner. The mini refuses to boot from this external SSD. The progress bar gets almost all the way across and then the mini shuts down. I have the setting in Startup Security Manger to allow external booting. I tried the troubleshooting steps that Bombich Software offers in this document:

Help! My clone won't boot! | Bombich Software

bombich.com bombich.com

Nothing worked. I did try the drive hooked up directly to a Thunderbolt 3 port on the mini and also hooked up to a USB hub (which was connected to a Thunderbolt port).

I'm out of ideas. My question is, what value does this drive have for making non-bootable backups of my internal drive? I don't have a second Mac I could use to re-image the internal drive (should it get corrupted) with the backup. As far as I know, there is no stand-alone boot program for Mac to image drives like Acronis offers for Windows PCs.

Since the Sandisk drive now has a copy of my internal drive, I am reluctant to return it, as I don't really trust any wiping/formatting I could do to it.

Any thoughts would be welcome.
Click to expand...

I think what you are experiencing is a failed cloning process whereby the cloned system has some form of corruption, or the system did not get fully copied over. In Mojave, you need to configure Carbon Copy Cloner to accept full secure booting by configuring the boot menu (new in Mojave) to allow private information to be copied over? Did you go through the "throw the fish" into the pond routine that Carbon Copy Cloner asked you to do when you run the software? Are you running a new version of CCC? If you did not throw the fish into the pond routine (throw fish icon into the secure boot menu), then what happens is that, the mini boots and detects some problem with the boot drive and tried to fix it. When it failed to fix the issue, it will shut down. This process happens to most macs, including older Minis.

If you can't copy a secured boot internal drive, my next recommendation would be to install Mojave onto the Sandisk and then do system migration afterwards. This will ensure all private secured information get transferred properly onto the Sandisk.

I think your Sandisk is bootable with your Mini, otherwise you won't see the progress bar and then the imminent shutdown.

Hope this helps.
 
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Fishrrman said:
If the connecting cable is removable -- have you tried a DIFFERENT cable?
Do you have access to another Mac? If so, do you get the same problem on the other Mac?

Another approach you could try:
- Download a new copy of the Mojave installer from the app store and put it into your applications folder
- Use disk utility to erase the Sandisk SSD to Mac OS extended with journaling enabled, GUID partition format.
- Launch the OS installer, and install a brand-new copy of Mojave onto the Sandisk SSD
- Does the install "go through"? If so, you should see the setup screen.
- Begin setup, and at the appropriate time choose to "migrate" all your stuff over to the new drive.

I realize this involves some work, but if the Sandisk still won't boot after doing that, I'm thinking that -something- inside of it (probably in the controller board) doesn't support booting on the Mac OS.
Click to expand...

I had an old, long USB-C cable from a MacBook, I tried that with the Sandisk, and this time the progress bar below the Apple logo quit even sooner before the mini shut down. I'm beginning to suspect that this may be a power problem to the drive, that at a certain point in the boot cycle the Sandisk is trying to draw too much power from whatever port it's connected to. Because with the shorter cable the Sandisk came with, the progess bar got farther to the right before the mini shut down. Oh well, I could be totally off base here.

As for installing Mojave on it, the Mac App store won't show me the installer. It says no results.
[automerge]1572796009[/automerge]
How do I get a copy of the Mojave installer?
[automerge]1572796230[/automerge]
iluvmacs99 said:
I think what you are experiencing is a failed cloning process whereby the cloned system has some form of corruption, or the system did not get fully copied over. In Mojave, you need to configure Carbon Copy Cloner to accept full secure booting by configuring the boot menu (new in Mojave) to allow private information to be copied over? Did you go through the "throw the fish" into the pond routine that Carbon Copy Cloner asked you to do when you run the software? Are you running a new version of CCC? If you did not throw the fish into the pond routine (throw fish icon into the secure boot menu), then what happens is that, the mini boots and detects some problem with the boot drive and tried to fix it. When it failed to fix the issue, it will shut down. This process happens to most macs, including older Minis.

If you can't copy a secured boot internal drive, my next recommendation would be to install Mojave onto the Sandisk and then do system migration afterwards. This will ensure all private secured information get transferred properly onto the Sandisk.

I think your Sandisk is bootable with your Mini, otherwise you won't see the progress bar and then the imminent shutdown.

Hope this helps.
Click to expand...

I remember the fish when I installed CCC in Mojave. In Catalina, I checked in Security & Privacy and CCC has Full Disk Access. Is there something else I need to check?
 
Never mind, I was able to get the link to Mojave in the App Store. Downloading it now.
 
Duncan68 said:
I had an old, long USB-C cable from a MacBook, I tried that with the Sandisk, and this time the progress bar below the Apple logo quit even sooner before the mini shut down. I'm beginning to suspect that this may be a power problem to the drive, that at a certain point in the boot cycle the Sandisk is trying to draw too much power from whatever port it's connected to. Because with the shorter cable the Sandisk came with, the progess bar got farther to the right before the mini shut down. Oh well, I could be totally off base here.

As for installing Mojave on it, the Mac App store won't show me the installer. It says no results.
[automerge]1572796009[/automerge]
How do I get a copy of the Mojave installer?
[automerge]1572796230[/automerge]


I remember the fish when I installed CCC in Mojave. In Catalina, I checked in Security & Privacy and CCC has Full Disk Access. Is there something else I need to check?
Click to expand...

You manually added the System Preferences application to the Full Disk Access in Catalina ontop of CCC? This is a known issue with Catalina preventing external boot access to be mounted.
 
When I try to run the Mojave installer app, I get the message that "This copy of the "Install macOS" application is too old to be opened on this version of macOS.

I am running 10.15.1 Catalina.
[automerge]1572798876[/automerge]
iluvmacs99 said:
You manually added the System Preferences application to the Full Disk Access in Catalina ontop of CCC? This is a known issue with Catalina preventing external boot access to be mounted.
Click to expand...

In the Carbon Copy Cloner menu in the app, it says it has full disk access.
 
After the Mojave installer wouldn't run, I downloaded the Catalina installer and tried to use that to install to the SanDisk SSD. It got started but then came back with the error message "Unable to verify macOS" (or something like that) and then it quit.

My conclusion is the SanDisk is not compatible with booting macOS. I'm just going to use the drive to archive some files.

Thanks for everyone's help.
 
You may have been on to something when you mentioned above that the Sandisk might not be receiving enough power to complete the boot cycle. You can test that by hooking it up to a powered hub. I have an external USB optical drive that requires a double USB 3 connection in order to properly work. Of course with the Sandisk, you can't use a double connector.
 
chscag said:
You may have been on to something when you mentioned above that the Sandisk might not be receiving enough power to complete the boot cycle. You can test that by hooking it up to a powered hub. I have an external USB optical drive that requires a double USB 3 connection in order to properly work. Of course with the Sandisk, you can't use a double connector.
Click to expand...

I have a four port powered hub hooked up to the mini. I tested the SanDisk on that hub, too. Nothing has worked.
 
Duncan68 said:
I have a four port powered hub hooked up to the mini. I tested the SanDisk on that hub, too. Nothing has worked.
Click to expand...

Okay, unless you have another use for the Sandisk, I would send it back for a refund. If it doesn't complete the boot cycle from a powered hub, it's very likely incompatible. I know a Samsung T5 will work, you might want to try that instead if you get a refund.
 
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Duncan68 said:
After the Mojave installer wouldn't run, I downloaded the Catalina installer and tried to use that to install to the SanDisk SSD. It got started but then came back with the error message "Unable to verify macOS" (or something like that) and then it quit.

My conclusion is the SanDisk is not compatible with booting macOS. I'm just going to use the drive to archive some files.

Thanks for everyone's help.
Click to expand...
The Sandisk will boot macOS just fine. Just try starting the Mini up from internet recovery and use that to install to the Sandisk.
 
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chrfr said:
The Sandisk will boot macOS just fine. Just try starting the Mini up from internet recovery and use that to install to the Sandisk.
Click to expand...

Thanks! That worked. Only I’m having to install a second time because I made the mistake of seeing if CCC would work with it, backing up from the internal to the SanDisk. It completed with errors and rendered the external unbootable.

So now I’m wondering how I’m going to keep the SanDisk updated? Is using Migration Assistant for this feasible?
 
Did the Sandisk come with any "proprietary software" installed on it? (from Sandisk)
Is there some kind of "Sandisk disk utility" app?
If there is, try to run it and see if there IS any "Sandisk software" on the drive.
If there is, I suggest you use the Sandisk utility to REMOVE any proprietary software.
Then... erase the drive and start over.
 
Fishrrman said:
Did the Sandisk come with any "proprietary software" installed on it? (from Sandisk)
Is there some kind of "Sandisk disk utility" app?
If there is, try to run it and see if there IS any "Sandisk software" on the drive.
If there is, I suggest you use the Sandisk utility to REMOVE any proprietary software.
Then... erase the drive and start over.
Click to expand...

The drive was erased in Disk Utility several times, and formatted at different points in macOS Journaled or APFS. I didn't see any software on the drive when I first plugged it in, but I think it was in a Windows format that Macs could read.

I will look into the documentation and check the SanDisk site to see if there is a utility app and/or any hidden software on the drive.

That said, the drive is booting an installation of macOS Catalina now. It seems to boot and work fine. Despite being half the speed of the mini's internal, I don't notice much of a difference.

My concern is with keeping it updated when I make changes to my internal drive, which will continue to be the drive I regularly boot from. The SandDisk is only for backup/just in case.

Edit: I checked and the drive doesn't come with any software installed. SanDisk offers a file encryption uitility, but you download it from their site and it doesn't work with APFS drives anyway.
 
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Wanted to add, I am now able to use the drive with Carbon Copy Cloner. The developer told me he thought I was running into an obscure bug and provided me with a special build of CCC that addresses it. Using this, I was able to clone my internal HD to the SanDisk and get the clone to boot.

So now I am able to use the SanDisk as I intended.
 
Did Mr. Bombich describe what it was that kept the drive from booting?
 
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