Moving my boot drive back to internal on Mac Mini

[MR_Boogy]

I have a 2012 MacMini running Mojave. Originally MacOS was on the built-in 1Gb HDD but I got an external SSD and set this up as the main drive for OS, applications, etc; I didn't feel comfortable installing an internal drive. I remember it being quite easy but I don't recall exactly how I did it. I do know my Mac cannot boot off the internal drive so I guess I removed the old OS entirely.

I am having more and more stability issues and am considering reinstalling the OS on the internal drive as a last attempt before biting the bullet and getting a new machine.

Ideally I wouldn't trash the 1Gb drive as it is where most of my files live; I'm wondering if I can move my applications across too. I might continue to use the external SSD but I do not want it as the boot drive.

Is this going to be difficult to achieve and a full wipe would be much easier? If it's reasonably straightforward, can anyone help me get started? I'm fairly techy but not got much experience with this sort of thing.

 

[Fishrrman]

Once you have been used to the speed of the external SSD, you are most likely NOT going to be happy with the SLOW speeds of the internal 5400rpm drive.

If you're experiencing "stability issues", my guess is that they ARE NOT coming from the external SSD itself (unless it's a cable or enclosure problem), but rather from the software that is ON the drive.

Solution:
If you think "it's hardware", get NEW hardware.
Get another USB3 SSD, use CarbonCopyCloner to clone one drive to the other.
Then make the new SSD your "booter".

Take the old SSD, erase it, test it with disk utility, and if it checks out OK, I'd use it for "secondary storage".

 

[MR_Boogy]

Well sometimes I find the Mac is running but it says it cannot see the boot disk. I had a theory it might be putting the external disk to sleep when not in use and killing itself... I also have issues where the machine hibernates then won't wake up, and where the monitor goes to sleep and won't come back.

Either way, booting off an external disk is not really good practice and I figured I'd take the machine back to spec. If it helps, I might just buy an internal SSD kit and figure out how to install it properly - but I don't want to buy new kit until I verify where the problem is. I can't STOP using the SSD drive until it's not the boot drive, and I don't want to buy another one only to find the issue was on the motherboard or the OS.

 

[Fishrrman]

"Either way, booting off an external disk is not really good practice and I figured I'd take the machine back to spec"

This is... no other way to say it ... Not So.

I've been booting and running my late 2012 Mini using an SSD mounted via an external USB3 connection since the day I took it out-of-the-box in January 2013.

It still boots and runs great... always has.

Do you have your energy saver pref pane set to put hard drives to sleep?
You don't want that.

 

[MR_Boogy]

Well at the very least you can knock the cable. I agree it SHOULDN'T be an issue but it's still not best practice and my Mac definitely has some sleep-related problems (that are getting worse) and I want to simplify to figure out where the problem is.

I wonder, could the external drive be self-sleeping when it's not in use? Seems a little far-fetched but I'm running out of diagnostics after over a year trying to figure it out.

• I use my Mac up to 8 hours a day and it NEVER has issues during use.
• I leave it on overnight and it used to work for weeks at a time. Then, every now and then in the morning I'd find it was (seemingly) running, but the screen was in standby and wouldn't wake up, forcing a hard boot.
• Then sometimes I'd find it was alive but showing the "no boot disk" or "your Mac had to restart" display screen.
• I started testing caffeinate which maybe helped a little.

Then more recently:

• it now restarts EVERY night almost without exception. Newer OS so maybe it just restarts rather than rebooting to a hold screen. I come in the morning and it's running but has rebooted.
• Sometimes it does it multiple times during the day, e.g. over lunch when I leave it for only an hour
• My display is set to turn off after 10 minutes which normally works fine but sometimes I come in after several hours and the display is still on

I have screen shut-off 10min, computer shut-off 1hr, disks NOT set to sleep if possible, ALLOW wake for network access.

The common theme to all these issues seems like sleep, since it only breaks when it's not used. It might be the drive has an issue or the USB cable or even the USB socket on the Mac. It might be a glitch in the motherboard relating to power management. It could be a MacOS bug - though this has persisted over 3 versions of the OS and though I do see some people having issues online, it's rare.

If the Mac itself is dying, I don't to buy a new disk and waste time migrating my boot drive across.
Even if I could get the Mac to boot off the internal disk without changing thing external one, I could run that way for a week and see if anything changes.

All a bit tricky. I'm tempted to say it's an old machine and get a new one, since I rely on it for work and time is money - but I really like this machine and the new Minis are very expensive.

 

[iluvmacs99]

Here are a couple of thoughts..

Since you had your OS on the external SSD from the start and while you may have updated the OS, you might not get the latest EFI boot rom and SMC firmware updated because Apple had recently changed the way they update the firmware. That is, when you run an OS installer on an external SSD that is not an Apple stock drive, you might not receive the latest EFI boot rom and SMC firmware and from what you are describing, it may have not received that. Under the system report, you can find out your EFI boot rom version. It should be 280.0.0.0.0 for a Mac Mini 6,1/6,2. Also check to make sure your SSD drive is formatted to APFS volume rather than HFS+. You also want to check if you have the latest USB 3 drive that is fully compatible with APFS booting, because after October 31st, 2018 which is when Apple changed the boot rom version identification and caused a lot of booting issues with USB 3 external drives, you can get the occasional no OS disk because Apple now treats USB 3 devices as secondary boot devices, whereas your internal drive, Firewire and Thunderbolt devices as primary in the Mac Mini 2012. Your option is to install an internal SSD drive, format it to APFS and re-install Mojave and update it. When you re-install the latest Mojave combo update, it will update the firmware and SMC firmware, so this ensures you have the most updated firmware supporting Mojave. M Do not carbon copy clone your OS and stick inside the Mac Mini 2012 as this "WILL NOT" update the firmware if your firmware is older than 280.0.0.0.0. After a new re-install, use either Carbon Copy Cloner to clone your external SSD to this internal SSD or use Migration Assistant to migrate the applications and data over. This should re-establish stability with Mojave installed Macs. If you do already have the latest EFI boot rom in your Mac Mini, then you should boot off an internal drive if you want that primary drive access after sleep, LAN wakeup etc..

Hope this helps.