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Mac Catalina : How can I merge 2 partitions into one?

In Mac Catalina , How can I merge 2 internal partitions into one?

Under Partition tab , minus symbol (-) is disabled

and I have tried through Terminal by using below commands

diskutil list

diskutil mergePartitions JHFS+Mac disk1s5 disk1s7

I'm getting below error while running above commands

Any help Highly appreciated , Thank you in advance

Usage: diskutil mergePartitions [force] format name

DiskIdentifier|DeviceNode DiskIdentifier|DeviceNode

Merge two or more pre-existing partitions into one. The first disk parameter

is the starting partition; the second disk parameter is the ending partition;

this given range of two or more partitions will be merged into one.

All partitions in the range, except for the first one, must be unmountable.

All data on merged partitions other than the first will be lost; data on the

first partition will be lost as well if the "force" argument is given.

If "force" is not given, and the first partition has a resizable file system

(e.g. JHFS+), it will be grown in a data-preserving manner, even if a different

file system is specified (in fact, your file system and volume name parameters

are both ignored in this case). Also, if "force" is not given, and the first

partition is not resizable, you will be prompted if you want to erase.

However, if "force" is given, the first partition is always formatted. You

should do this if you wish to reformat to a new file system type.

Merged partitions are required to be ordered sequentially on disk.

See `diskutil list` for the actual on-disk ordering; BSD slice identifiers

may in certain circumstances not always be in numerical order but the

top-to-bottom order given by diskutil list is always the on-disk order.

Ownership of the affected disk is required.

Example: diskutil mergePartitions JHFS+ NewName disk3s4 disk3s7

This example will merge all partitions *BETWEEN* disk3s4 and disk3s7,

preserving data on disk3s4 but destroying data on disk3s5, disk3s6,

disk3s7 and any invisible free space partitions between those disks;

disk3s4 will be grown to cover the full space if possible.

MacBook Air 13", macOS 10.15

Posted on Nov 25, 2019 11:03 AM

Top-ranking reply

Kurt Lang

Level 9

61,908 points

Posted on Nov 26, 2019 6:25 AM

You don't need to. In APFS it's actually a shared partition type of setup (not really the right way to put it). It's a bit easier for me to explain it this way:

If you've ever set up a server, you'll notice that you create separate share points, also sometimes called a shared folder in the server settings. What you're really doing is simply creating a folder on the server that remote computers logging in see as a drive. You create the separate share points to divide who can access what on the server. Such as, only office personnel can access the files in the Accounts share point folder by being the only employees with the login password.

Let's just say you have a 4 TB server, such as a desktop NAS. Because share points are just folders, they all have the access to the same 4 TB of space to save files.

That's basically how the new APFS works. You can still break off actual partitions if you want, but APFS also allows a partition to be "dynamic", so to speak. In other words, you could break a 2 TB drive into 4 partitions, but they will all have access to the full 2 TB of space since they aren't divided off into hard partitions.

All of that means you don't need to try and control how much space the read only section of Catalina uses. Both it and the Data partition share the same total space.

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Mac Catalina : How can I merge 2 partitions into one?

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