You May Not Install to This Partition Because the Computer Is Missing a Firmware Partition

For years, early adopters and beta testers would segmentation their Mac’s hard drive in order to test macOS, either a new or beta version. Partitioning your hard bulldoze actually creates a split up container on your hard drive that is limited in its abilities.

If your Mac uses
APFS, y’all tin actually create a volume right on your current difficult drive instead. This allows your hard bulldoze to dispense your available storage temporarily as y’all need information technology. It makes testing new or beta operating systems much easier to do and information technology’s easier to remove when you’re done testing them out.

What’south the difference between a disk division and a volume?

A partitioning and a book human action in very like ways, but creating a volume allows for flexibility of storage needs while creating a partition separates storage with a specific amount and does not adjust for each drive’s needs.

What is a partition?

Partitioning your Mac is basically splitting your hard bulldoze into separate, usable systems. It makes information technology possible to run ii dissever operating systems on 1 device, similar Windows and macOS, or two versions of macOS (like Catalina and Big Sur).

Note: If you want to run Windows on your Mac, Apple’southward Boot Military camp assistant will automatically brand a division for yous.
Hither’s how to install Windows.

It is important to note that partitioning your difficult drive also splits upwardly your available hard bulldoze space. Each partition will take upwards a portion of your usable storage. So, if y’all are running low on storage chapters on your hard drive, we don’t recommend partitioning.

If y’all are running a Mac using HFS+ file system (prior to macOS Catalina) you must partition your difficult drive. If your Mac uses APFS, Apple tree recommends creating a book instead.

What is an APFS volume?

An APFS book creates a similar container to be used the same fashion every bit a partition, but information technology mounts information technology within your main hard drive. This allows the volume the flexibility to grow or shrink in storage size as needed. You lot don’t have to worry near running out of temporary space while installing macOS, for example, considering information technology volition grab the necessary space from your master drive and so put it back when it’south done. Y’all can manually select size limiters for a book if you’re worried about 1 drive overtaking another’due south infinite.

If your Mac uses APFS, Apple tree recommends creating a book instead of a partitioning.

How to add an APFS book on Mac

You tin can test Large Sur on your Mac without having to change anything on your daily driver by creating a book that acts equally a separate drive so you can install a completely different operating system. This allows you to switch betwixt OSes using the Startup Deejay option.

1. Open
   Finder
   from your Mac’s dock.

2. Select
   Applications.

   
   
   Source: iMore
   

3. Gyre downwardly and open the
   Utilities
   folder.

4. Double-click on
   Disk Utilities
   to open it.

   
   
   Source: iMore
   

5. Select your
   APFS drive
   (Should be called Macintosh HD) from the sidebar.

6. Enter a
   name
   for the volume.

   
   
   Source: iMore
   

7. Select the type of
   APFS format
   you desire. I recommend only APFS.

8. Click
   Add together.

   
   
   Source: iMore
   

You take the option of selecting a specific size that you desire the volume to be, which will guarantee this volume will always have the
reserve size
you desire. However, APFS volumes are designed to allocate disk infinite as needed. If you’re worried nigh running out of disk space on either your main bulldoze or the new volume, you can select a minimum/maximum book size. Afterward completing Step 7 above:

1. Click
   Size Options.
2. Enter a
   Reserve size
   to ensure that the new volume will always have a minimum amount of space.

3. Enter a
   Quota size
   to ensure your primary drive never runs out of space.

   
   
   Source: iMore
   

4. Click
   OK.

5. Click
   Add.

   
   
   Source: iMore
   

How to create a partition on your Mac

1. Open up
   Finder
   from your dock.

2. Select
   Applications.

   
   
   Source: iMore
   

3. Scroll down and open the
   Utilities
   binder.

4. Double-click to open
   Deejay Utility.

   
   
   Source: iMore
   

5. Select your
   hard drive
   in the Disk Utility window. It volition be the first drive on the list. It might exist named “Fusion,” or “Macintosh HD.”
6. Click on the
   Partition
   tab. You will be prompted to either add together an APFS volume or a Partition.
7. Click
   Sectionalisation.

8. Click the
   Add together partition push
   information technology looks like a plus (+) symbol.

   

9. Change the size of the segmentation you wish to use by dragging the resize controls. The used space is represented in blue.
10. Name the new partition.
11. Specify which file system format yous want to use. If you’re running macOS 10.thirteen or higher, y’all’ll desire
    APFS. If you lot are running macOS 10.12 or older, you’ll desire
    Mac Bone Extended.

12. Click
    apply.

    

Disk Utility will check the disk and make changes. This will accept several minutes.

How to switch partitions or volumes

You tin can switch to the new segmentation, install the current macOS, and then download and install macOS Catalina from there.

1. Click the
   Apple icon
   in the upper-left corner of your screen.

2. Select
   Arrangement Preferences
   from the drop-down bill of fare.

   

3. Select
   Startup Disk.

4. Click the
   Lock
   in the lower left corner of the window to unlock and brand changes.

   

5. Enter your system admin password.
6. Click
   OK.
7. Select your
   partition bulldoze.

8. Click
   Restart.

   

You tin also restart your Mac and printing the Option Central when you lot hear the startup chime. This volition accept you to the Startup Director and you tin select your drive from there.

You lot will then be asked to install macOS. This volition install the latest available macOS onto the partitioned difficult drive. You lot may accept to install an older version of macOS before updating information technology to the more recent version you want to run.

If you are testing a beta version of macOS, yous’ll beginning install whatever the current version is. Then, you can then install the macOS beta.

How to download macOS Big Sur

If macOS Big Sur doesn’t automatically install on your partitioned hard drive (if information technology installs macOS Catalina instead, for case), you lot can install it from your System Preferences in
About this Mac.

Subsequently you have macOS Catalina installed, you can follow the instructions to download and install macOS Big Sur.

• How to download macOS

In the marketplace?

If yous’re looking for a new Mac, check out our list of our
favorite MacBook models of the year.

Whatever questions?

Practise you have any questions about installing a partition or downloading a new operating arrangement onto a partitioned drive to test macOS? Allow us know in the comments. If you’re having problem division your difficult bulldoze, be sure to
cheque out our forums
for assist!

Updated November 2020:
Updated for the public version macOS Big Sur.