Can't Partition Drive - HELP!

[Twijit]

Hello all,

I'm wondering if someone can help me. Experiencing a strange issue in Disk Utility preventing me from partitioning (to install Monetary beta).

First things first. When I open Disk Utility it says I'm using around 365GB of space, which isn't correct. I have 243GB available when I check storage under "About this Mac". I'm pointing that out in case it helps in figuring out what comes next.

Read on...

When I go to partition the drive I see three partitions. Once sized at 524MB, which I'm guessing is recovery.

And one sized at 5.37GB, which I suppose is the OS.

And of course, what remains in the data partition, which again is saying I'm using more space than I am and won't allow me to partition. Any thoughts?

 

[NC_Bulldog]

I just looked at my startup 500 GB SSD in Disk Utility. The display is much like yours and tells me I can't create a new partition.

However, if I right-click on the Container I am given the option to "Add APFS Volume..." You SHOULD be able to create the new volume and install the Monterey Beta in it. I have never run into a problem with having different macOS versions residing in different APFS volumes within the same "Container."

Obviously -- have a bootable backup of this drive in case something goes wrong so you can restore it as needed!

 

[joevt]

You can put multiple OS volumes in the same APFS container but I prefer to keep them separate. You should be able to click on the Macintosh HD container and click the + button to split it. Your last screenshot has has the + button obscured.

Actually, it says the container can't be split which is strange. I wonder if it's because it's a Big Sur partition? No, I can split my Big Sur partition. The problem is the used space / minimum size are wrong. Did you try to First Aid everything?

 

[joevt]

If First Aid on everything (media, container, etc.) doesn't fix things then report the output of the following commands:

diskutil list
diskutil info -all
diskutil apfs list

 

[DeltaMac]

You don't need to partition anything, just add a new volume to the container.
Go to your first screen in Disk Utility, then choose the Container disk3 line.
In the menubar of that Disk Utility window, click on the (+) above Volume to add a volume to the container. (Name it something!) -- Click the Add button.
I suggest that you don't choose to make that new volume some different size, the new volume will use whatever space it needs to use (a neat feature of APFS volumes)

 

[NC_Bulldog]

I just looked at my startup 500 GB SSD in Disk Utility. The display is much like yours and tells me I can't create a new partition.

However, if I right-click on the Container I am given the option to "Add APFS Volume..." You SHOULD be able to create the new volume and install the Monterey Beta in it. I have never run into a problem with having different macOS versions residing in different APFS volumes within the same "Container."

Obviously -- have a bootable backup of this drive in case something goes wrong so you can restore it as needed!

Since my SSD, like yours, was unable to be partitioned because Disk Utility said there wasn't enough disk space, I decided to investigate further. It turned out I had a lot of "Snapshot" files taking up GBs of disk space.

In Terminal enter tmutil listlocalsnapshots /

This lists all the Snapshots being stored.

In my case some were Time Machine snapshots. All of them can be deleted by entering

sudo tmutil deletelocalsnapshtots /

In addition, I use Carbon Copy Cloner to create clones. I had specified it to also store its Snapshots on the SSD. Using CCC to display the Snapshots it had created, I manually deleted each of them, since I didn't need them at this time.

After removing all the Snapshots on the SSD, I had now cleaned up enough space on my SSD to Partition the drive -- if that's what I wanted to do.

 

[Twijit]

Wow, thanks so much for the help. You guys are awesome!