macOS – How to Install OS X on External Drive Partition

installmacospartition

There are plenty of articles explaining how to install OS X on a separate partition of your Mac’s internal drive and how to install it onto an external drive using a single partition. However, it’s not clear to me whether it’s possible to install OS X onto a separate partition of an external drive. It’s what I’d like to do, is it possible?

For what it’s worth, my external drive currently has a single 500GB partition, is formatted as “Mac OS Extended (Journaled)” and has a GUID Partition Table. That should make it bootable, right?

Best Answer

Yes!

As the disk is the correct format, it will show in the disk list in the installer (click Show All Disks). You can install any version of OS X on a partition of the correct format, regardless of where the partition is located.

The OS X installer doesn't partition the disk for you though; do this first in Disk Utility.

Related Solutions

Formatting Boot Drive As Encrypted For Clean Install

If you format a drive as Encrypted, you are in fact turning on File Vault, as that's the only encryption layer that OS X supports. The main advantage of partitioning the drive as Journaled, and then turning on File Vault is that you can revert the drive to a simple unencrypted volume if you should choose to do so in the future. You can't do this with a volume that was formatted directly as Encrypted. Other than that, the end result is the same.

BootCamp partition error even though the drive is one partition

I was able to install Windows after doing two things. I'm not positive which one did the trick as I did them both in between an attempt to run bootcamp. These are the things I did in order:

Install reFind... doing this added the missing EFI partition that was mentioned I was missing in the comments for this question.
Use the reFind partition editor to fix the Master Boot Record (MBR) table for my HDD. This partition editor can be found on the reFit menu (launched by choosing the reFit option on the reFind menu)

After this, I launched mac, started boot camp, and the 'status: partitioning disk' message/bar restarted and then it was able to finish partitioning and I have since installed Windows successfully. Any hints on why this finally worked would be much appreciated!

Also, something to note is that after I installed reFind, my partition table (output to diskutil list) was:

/dev/disk0 (internal, physical):
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:      GUID_partition_scheme                        *500.3 GB   disk0
1:                        EFI EFI                     209.7 MB   disk0s1
2:                  Apple_HFS MAC HDD                 500.1 GB   disk0s2

Best Answer

Yes!

Related Solutions

Formatting Boot Drive As Encrypted For Clean Install

BootCamp partition error even though the drive is one partition

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