Resizing External Backup Volume on Mac Mini Pro M4

OK I thought that you had Partitioned the external drive.

From > Add, delete, or erase APFS volumes in Disk Utility on Mac - Apple Support

To Delete an APFS volume

When you delete a volume, all the data on the volume is permanently erased, and the volume is removed from the container.

1. Go to the Disk Utility app on your Mac.
2. If Disk Utility isn’t open, click in the Dock, type Disk Utility in the Search field, then click Disk Utility.
3. Select the APFS volume you want to delete in the sidebar.
4. Click - in the toolbar.
5. If the button is dimmed, the selected volume can’t be deleted because it’s in use. To delete the volume, you need to open Disk Utility in macOS Recovery.
6. Do one of the following:

• • If you selected a volume group: Click Delete to delete the volume group.
  • If you selected a volume that’s a member of a volume group: Click Delete Volume Group to delete the volume group, or click Delete to delete only the selected volume.
  • If you selected a volume that isn’t a member of a group: Click Delete to delete the volume.
  • When the operation is finished, click Done.

Manage your files and folders with Finder. Please see the guidance here: Use the Finder on Mac - Apple Support

As for the external drive. There's no need to mess around with Terminal at all. Disk Utility is what you want to use.

Disk Utility User Guide for Mac - Apple Support

Your Time Machine backup drive should be formatted with APFS. When your drive is formatted with APFS, the entire capacity of the drive is shared by any volumes that reside with the APFS Container that is created. There is no need to resize those volumes or the container by partitioning. APFS adjusts the volumes on the fly, allocating space to them as their capacity needs grow and shrink.

Add, delete, or erase APFS volumes in Disk Utility on Mac - Apple Support

Any drive that will only be used with the Mac should be formatted with APFS.

If you must share with a PC, then use ExFAT.

The Mac works in ways the PC can't.

If all of your files are still intact on the Mac mini, then I would say the easiest way to accomplish what you want to get done will be to erase that external drive and start a fresh Time Machine backup tonight.

You WILL use Disk Utility to do this. You DO NOT need to use Terminal and you DO NOT have to start up in recovery mode to work with external drives.

1- Launch the Disk Utility app.

2- In the Disk Utility app click the View button and select Show All Devices (or select View from the menu bar and then Show All Devices.

3- Select the external drive device that you want to erase. Don't just select an indented volume below the device select the device itself.

4 - Click the Erase button. On the Erase window that appears, select the GUID Partition Map for Scheme, Select APFS as the Format and then type a name for the drive.

5- Click the Erase button.

That's it. Done.

The Disk Utility window:

The Erase disk window:

vkinetic002 wrote:

I have a 2TB external drive for backups. I initially setup a 1TB Volume for Backups. There is roughly 1TB unused space on the physical external hard drive. I want to increase the space for the Backups to the maximum 2TB. Not having any luck with 'sudo diskutil apfs resizeContainer disk4s2 0'. I get the message:

Error -69743: The new size must be different from the existing size

I suppose I could just blow away the volume and start all over but I do want to keep the original backups that began from the time I first stated the Mac Mini. Note that I am a complete Apple novice having extensively and exclusively used PCs all my life. I did have to turn off encryption on the Backup drive in order to attempt the resize. Can anyone help?

You can only add the second partition back to the first partition.

If the backups are on the second partition, then you need wipe and format the drive back to one partition.

Also can someone please tell me how to create a new folder within another folder? I can create a new folder from the upper right hand drop down in Finder but it creates a folder in the root directory which I then have to move to where I really want the new folder, Surely there is an easier way to do this?

Select and open the Folder that you want to create the new folder in.

As a general rule of thumb it is foolish to limit a backup External Hard Disk to NOTHING OTHER THAN BACKUPS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

This means if you are going to use an External Hard Disk for a backup, NEVER EVER use it for anything else! Why, very very simple. All HD (internal and external) die, when no one can predict as they have mechanical parts and mechanical parts eventually die. So when they die you lose everything (backups, data, whatever) on the drive. Be smart and only use an External Hard Disk relegated to backup duty to only that task. Don't be cheap and lose your data, playing that game you lose just like a gambler always does.

You're welcome.

You're welcome. Good work. Now you understand the importance of using a dedicated external drive for Time Machine and different external drives for other file storage.