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mynikonF3

macrumors newbie
Original poster
Oct 1, 2025
9
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Montreal, CANADA
Hello Mac Mini Forum,

I got this refurbished i7 Mac Mini and Mojave occupies like 60+% of the hard drive. And these HD's can't be swapped out.

Do I have any alternatives? All I can think of is getting an external drive with Thunderbolt and booting from that to leave my on board hard drive freed up.

Can you folks enlighten me and or provide alternatives without incurring huge costs. OWC dropped the price from 1300$ to 400$ CDN.

Thanks for helpful skinny!
 
"Do I have any alternatives? All I can think of is getting an external drive with Thunderbolt and booting from that to leave my on board hard drive freed up."

You should have considered the issue of "drive space" before you bought a 2018 Mini with a tiny 128gb SSD, but that's water under the bridge now.

You could sell what you have and get one with more space. I would recommend NOTHING LESS than 1tb these days.

Or... you could get an external SSD and boot and run that way.
I'd suggest USB3.1 gen2 as the best balance of speed and price.

My recommendation:
BTW, that's a GREAT price right now for 2tb.
I bought one of these some months ago, and paid about $90 ... for just 1tb.
In any case, it's small and fast... as nice as they get.
 
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"Do I have any alternatives? All I can think of is getting an external drive with Thunderbolt and booting from that to leave my on board hard drive freed up."

You should have considered the issue of "drive space" before you bought a 2018 Mini with a tiny 128gb SSD, but that's water under the bridge now.

You could sell what you have and get one with more space. I would recommend NOTHING LESS than 1tb these days.

Or... you could get an external SSD and boot and run that way.
I'd suggest USB3.1 gen2 as the best balance of speed and price.

My recommendation:
BTW, that's a GREAT price right now for 2tb.
I bought one of these some months ago, and paid about $90 ... for just 1tb.
In any case, it's small and fast... as nice as they get.
I guess I was expecting far too much from OWC to advise me on OS size requirements and what I was doing. I have a couple of 2TB SSD's that I use for Time Machine and the other for my photography and graphic work on my Mini 2010 running High Sierra on a 1TB internal drive. OWC was trying to get me to buy a 2TB Thunderbolt drive. I didn't bite. Learned from my mistake.
 
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Hello Mac Mini Forum,

I got this refurbished i7 Mac Mini and Mojave occupies like 60+% of the hard drive.

That seems high. Mojave should be less than 25GB (not counting 3rd party apps but I recall that would include Xcode). Maybe it came preinstalled with the full GarageBand, iMovie, etc? If you didn't do a clean install when you first got it, I would look at that next unless you really need something that was preinstalled on it.

And these HD's can't be swapped out.

Do I have any alternatives? All I can think of is getting an external drive with Thunderbolt and booting from that to leave my on board hard drive freed up.

That should work and will feel close to native/internal SSD speeed. However, if you think you'll be fine with the builtin drive assuming the OS is only using < 25GB of the 120 GB then I would look at fixing that before spending the money on an external drive (ball parking ~ $US 300 for a TB3+ with 2GB SSD when all is said and done).
 
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Thanks for that skinny. OWC installed the OS for me. They told me the cpu came with the OS and wanted to know which I wanted installed. I said the lightest, so they installed Mojave. I appreciate all your insight.
 
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Thanks for that skinny. OWC installed the OS for me. They told me the cpu came with the OS and wanted to know which I wanted installed. I said the lightest, so they installed Mojave. I appreciate all your insight.

Mojave is the lightest. In theory Catalina should be lighter but wouldn't swear that's true in practice. Catalina does enable access to newer applications (e.g. later versions of browser) than Mojave at the expense of losing access to older applications. After that Monterey enables better compatability without much downside to Catalina.

As far as the OS's disk usage. Just checked my Mac Mini under Mojave and I'd ballpark the OS's usage at 17GB not counting optional Apple programs, Xcode, 3rd-party applications, my files, etc.

I have no idea how their installation of it on your system is getting to 70+ GB.
 
Mojave is the lightest. In theory Catalina should be lighter but wouldn't swear that's true in practice. Catalina does enable access to newer applications (e.g. later versions of browser) than Mojave at the expense of losing access to older applications. After that Monterey enables better compatability without much downside to Catalina.

As far as the OS's disk usage. Just checked my Mac Mini under Mojave and I'd ballpark the OS's usage at 17GB not counting optional Apple programs, Xcode, 3rd-party applications, my files, etc.

I have no idea how their installation of it on your system is getting to 70+ GB.
I agree Mojave ran great in my 2010 MBA 4GB intel in 2018....cringe....as Catalina was s sloth.

ya know I have 2 spare ssd drives, perhaps I can Mojave one today since I'm fidgety now.
 
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So, would I boot up my Mini 2018 in Recovery Mode (+Opt. +Cmd. +R) run Tools then go to the reinstall OS choice and reinstall Mojave? Will there be a base install selection...?
Thanks folks for the skinny...

(I don't suppose I can do that from Screen+OS share while I'm booted up on my 2010 Mini.) as I have my 2018 ethernet'd to my 2010 mini.)

or just simpler to shut down my 2010 min and plug my monitor into my 2018 mini and boot from it in Recovery....

You guys are great!
 
Don't know if it helps, but I can offer a couple insights. I used a 2014 Mini on Mojave for a number of years as a media server, it was basically just a "plain vanilla" Mojave install with all my media on an external 4tb ssd. Replaced it with a base m4 Mini last year, but just had a look and that Mojave disk only had about 38gb on it. So, apparently your installation is twice as large as mine (38gb is about 30% of 128gb). I didn't do anything to save space on that machine, it's just a standard installation.

Now, the base m4 Mini that replaced it has a "plain vanilla" install of Sequoia, which uses about 47gb of disk space. So, Sequoia is little larger but would still only be around 37% of a 128gb disk. I guess you could wipe your Mini and re-install, which might get you closer to my numbers.
 
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What you could do...

BACKUP all your personal data and apps currently on the internal drive.

Then...
Boot to a special version of INTERNET recovery.
You MUST use the following command:
Shift+Option+Command+R

This will force the internet recovery installer to install the original version of the OS that shipped with the 2018 Mini -- which is Mojave.

If you use "regular" internet recovery (Option+Command+R), you will get a later version of the OS (may not be what you want).

So... be sure to use the special one above.

Once you're booted to internet recovery, go to disk utility first.

IMPORTANT:
BE SURE to go to the "view" menu and choose "show all devices". You can't see the internal drive unless you do this.

Now look at the list on the left. The top line is the physical SSD inside.
Click on it to select it, then click erase.
Erase to APFS, GUID partition format.

Once the erase is done, quit DU and open the installer.
Does it offer you Mojave?
Then... go ahead and install.

When done, you'll see the welcome screen (choose your language).
NOW IS WHEN YOU NEED TO START CONSIDERING...

You probably DON'T want to migrate much of "your stuff" from before -- that's how the drive got filled up.

So consider very carefully which apps you really want to have on the internal drive. Be selective.

You can set up an account, but again, you may not want to keep your "large libraries" (pics, music, movies) on the internal -- they'll fill it up quickly. These items can be kept on an external drive and accessed that way.

I'd probably try to keep 30+gb "free" on the internal, for use for caches, temp files, etc.

Perhaps something here will be of used to you...
 
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So, would I boot up my Mini 2018 in Recovery Mode (+Opt. +Cmd. +R) run Tools then go to the reinstall OS choice and reinstall Mojave? Will there be a base install selection...?
Thanks folks for the skinny...

(I don't suppose I can do that from Screen+OS share while I'm booted up on my 2010 Mini.) as I have my 2018 ethernet'd to my 2010 mini.)

or just simpler to shut down my 2010 min and plug my monitor into my 2018 mini and boot from it in Recovery....

You guys are great!

One alternative to Internet Recovery is to create a bootable USB installer drive. There are various How-To's for this on the Interenet, and here's Apple's:
 
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Hello Mac Mini Forum,

I got this refurbished i7 Mac Mini and Mojave occupies like 60+% of the hard drive. And these HD's can't be swapped out.

One other thing came to me since you posted this -- did you enable iCloud and iCloud Drive on the account you created on this computer? If you have a lot of things on your iCloud Drive, etc, the system may be caching as much as it can from iCloud to your system drive. In which case reports of how much space is being used or how much is left may be misleading.
 
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As far as the OS's disk usage. Just checked my Mac Mini under Mojave and I'd ballpark the OS's usage at 17GB not counting optional Apple programs, Xcode, 3rd-party applications, my files, etc.

I have no idea how their installation of it on your system is getting to 70+ GB.
Same here. My System + Library are just under 17 GB on my computer running Mojave. Perhaps OP should post a screen shot of the boot drive listing each folder's sizes.
 
Same here. My System + Library are just under 17 GB on my computer running Mojave. Perhaps OP should post a screen shot of the boot drive listing each folder's sizes.
Thanks, guys, I have no idea what OWC did when they installed this. Now Apple System Preferences wants to install an even heavier OS. NOT going there, for sure. OWC customer service in there is useless. They're just pushing product. I even upgraded the RAM to 32mb at the time of order. We live in another paradigm I'm afraid.
 
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OP:
"I have no idea what OWC did when they installed this."

What does the post above mean? What exactly did they "install"?

You can't change the size of the internal drive on the 2018 Mini.
It is what it is.

If that's not enough to serve as a boot drive (even a "slimmed down" boot drive), then you need to buy an external SSD and set that up as the new boot drive.

I gave you a good suggestion as to what kind of SSD to buy in reply 3 above.

Just ...
1. get an external SSD (USB3.1 gen2 should do)
2. initialize it with disk utility to APFS
3. open an OS installer and install a copy of the OS onto it.
4. set it up and use it.

If you want Mojave, try booting to a special version of internet recovery:
Command-SHIFT-OPTION-R

If you want the most recent version of the OS that will run on it, boot to the regular version of internet recovery:
Command-OPTION-R
 
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Same here. My System + Library are just under 17 GB on my computer running Mojave. Perhaps OP should post a screen shot of the boot drive listing each folder's sizes.
i switched back to Mojave yesterday and will use this OS for that MacBook Air 2010 now for all my work.
i feel more comfortable with an older OS while using some 36Bit software.

OWC mac-sales will ship the latest OS install of what that mac can host.
luckily computers ares still bootable to Snow Leopard to Tahoe via a thumb drive.
 
OP:
"I have no idea what OWC did when they installed this."

What does the post above mean? What exactly did they "install"?

You can't change the size of the internal drive on the 2018 Mini.
It is what it is.

If that's not enough to serve as a boot drive (even a "slimmed down" boot drive), then you need to buy an external SSD and set that up as the new boot drive.

I gave you a good suggestion as to what kind of SSD to buy in reply 3 above.

Just ...
1. get an external SSD (USB3.1 gen2 should do)
2. initialize it with disk utility to APFS
3. open an OS installer and install a copy of the OS onto it.
4. set it up and use it.

If you want Mojave, try booting to a special version of internet recovery:
Command-SHIFT-OPTION-R

If you want the most recent version of the OS that will run on it, boot to the regular version of internet recovery:
Command-OPTION-R
Thanks, @Fishrrman I see my options. I'm just creating an emergency boot on a USB stick. Many thanks! EVERYONE. Will update as I progress.
 

mynikonF3 is your ssd or hd APFS formatted?​

why I mentioned this is:
I have 2 ssd drives on a MacBook Air 2010 as the APFS with a OWC blade now is not working.
trackpad keyboard won't respond after a 2020 upgrade I should have skipped,
while the Mac Journaled formatted drive is 100% but slower since that as a 2010 ssd drive.
when you get settled try using a Mac journaled format since that is stable and workable
though APFS is secure and untied better, but will gouge GB space, for some reason.

128GB is do able since Mojave is under 7GB but you need to use more external hard drives.
my MacMini is 265GVB but had octpopus-es 4 external drives of files, FLAC music, movies etc,

anyway im thinking about getting a Mac mini intel from them since i'm tired of the M silicon space fights.
 
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