MediaKit reports partition (map) too small" in Disk Utility

Ok, thanks for trying. You are not paying close enough attention to HWTech's post.

Notice how in your screenshot there is no Scheme option at all. That means you have not selected the top level of the drive. You only think you have, but you've selected the volume not the drive. You probably see something like this:

Go to the View menu and select Show All Devices:

After that change, you will see the actual drives. Note below they are "Apple SSD..." and "Samsung PSSD T7...," names of manufacturers and products, not OS-/user-applied volume names like 'Macintosh HD' or 'Backup'.

Now, you can see and select the actual top level of the drive and with that selected, when you click Erase you should see the option to select the partition scheme. That's what is currently set to Apple Partition Map and what you need to set to GUID.

With the drive mounted, in Disk Utility click Erase.

In the dialog that pops up click on Scheme. You should see three options:

You want to pick option 1, GUID Partition Map. Do that, then click the Format popup and you should see the full range of options:

If Scheme is set to option 2, Apple Partition Map, then you have just the MacOS Extended and FAT options:

If you see something different than the images above, post back. Set scheme to GUID, then you can set MacOS Extended (Journaled), then click Erase.

After that completes, select the Partition button at the top and establish your partitions as desired.

Revelstokian wrote:

I appreciate that everybody's trying to help by telling me what options to take....but my problem is that I'm not receiving the options that are current, as can be seen by my screenshot.

Your screenshot demonstrates nothing of the sort. It shows that the drive has an Apple Partition Map scheme and that you clicked the Partition button in Disk Utility.

The point being made by me and @HWTech is that you need to start by Erasing the drive, which will allow you to select GUID as the partition scheme.. To do that, click the Erase button, not the Partition button.

When you do that, you should see that you're being asked if you want Erase the drive.

That's where you can set it to GUID.

Not odd, expected with:

You need to click the Erase button in Disk Utility, set the Scheme to GUID Partition Map. Choose MacOS Extended Journaled if that's your preference. Once done, click the Partition button and proceed.

You have to start over and erase the whole physical HD in order to change the partition layout type. See the following Apple article from the Internet Archive (I think it is easier for people to understand since it includes pictures whereas the current version of that article does not):

https://web.archive.org/web/20250909095655/https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac

FYI, erasing the whole physical drive will destroy all data on that drive in both partitions. Make sure your data on that drive is backed up first.

Revelstokian wrote:

I have erased the hard drive many times. It's a brand new hard drive with nothing on it. I only receive the two apple format options. I guess the question is why would I only be offered the old formatting version. Like I said previously, I'm running a M2 Mac Studio with Tahoe.

Read the directions I linked very carefully & look at the picture at the top of that article. Disk Utility hides the physical drives from view by default (ever since macOS 10.13 High Sierra). You cannot change the partition type until you select the whole physical drive as described & shown in that article.

These are the three steps you are missing.

Revelstokian wrote:

Thank you, thank you, thank you. I completely forgot the step to "Show all Devices". I feel so stupid. All is well. The hard drive is formatted in APFS and partitioned. Thank you so much everybody.

You're welcome. And Congratulations.

It is partially Apple's fault for making these things so complicated these days. Apple has tried to simplify & hide things from users, but at the same time made those same things much more difficult & confusing as well. There are certain aspects of macOS which confuses & frustrates me as well.

FYI, when multiple contributors (especially higher level ones) keep repeating the same thing, step away for a bit & come back with a fresh open mind to re-read their suggestions. It is easy to become overwhelmed & frustrated. I cannot tell you how many times I have gotten stuck & gone back later on with a fresh look to discover I had overlooked something simple. I have kicked myself a lot over the years & felt equally embarrassed by the oversight/mistake. It happens. Live & learn. I'm glad you got things sorted out.

And we were glad to assist you.

Revelstokian wrote:

I have used Macs since 1992. I teach people to use a Mac. I've formatted many hard drives before. This time, I've had a problem and posted it here. What I'm trying to point out is that, I'm not receiving the normal formatting options, as I showed in my screenshot. I've done everything that's been suggested, but nothing's changed...

You screenshot does not show that you've tried following the advice in this thread. You don't need to convince us, but you seem to think you have and you're wrong about that.

You seem confused about the difference between Erase and Partition, because you keep saying you've erased the drive and then you reference a screenshot of the Partition dialog box showing that you are using an ancient partition map scheme (Apple Partition Map) that is intended for 20 year old computers. If you have actually erased the disk (at the top level as HWTech points out), then why do you keep choosing to use the wrong partition scheme for a modern Mac?

The solution to your problem is in this thread, I suggest you actually read it carefully. Regardless, I'm going to give up at this point and wish you luck.

Backing up a step, why are you using MacOS Extended (aka HFS+) formatting? If the external drive is a spinning disk, that makes sense. If it's an SSD, use APFS.

That said, Disk Utility in Tahoe does not appear to fully support MacOS Extended formatting any longer. See this page:

File system formats available in Disk Utility on Mac - Apple Support

If you set the version dropdown to Sequoia or earlier versions, MacOS Extended reappears as an option. I may be reading too much into this, since when erasing a disk in Tahoe in DU, I still see the MacOS Extended formatting options.

If you format as APFS, partitions are not recommended but rather you can create multiple volumes in the container. There are some cases where you may want to physically partition the drive (e.g. multiple Macs backing up to it via Time Machine, but for that use case you can also set a limit in TM settings).