Why it shows 135 in "disk utility list" when I have 256 GB of memory

partosi wrote:

I tried to install Linux on my MacBook in Dual Boot mode and allocated space for it on the disk. However, the installation failed with an error, and the allocated space was not returned. Is this a bug? What should I do? Do I need to install a new SSD?

You will need to erase the entire SSD and reinstall the operating system. You will have to use Recovery Mode in order to erase the entire drive. See How to reinstall macOS - Apple Support

Once you have a good backup, then you can try using the following instructions as a guide. I cannot give you exact commands to use because the device identifiers can change each time you boot & how you are booted. I'm not sure if these commands can be used while booted into macOS....you may need to boot into Recovery Mode to perform these commands.

My instructions will reference the information shown in your original post from the "diskutil list" output so make sure to get updated information & modify these instructions accordingly.

Show the drive layout for the internal drive in order to get the current device identifiers:

diskutil  list  internal

Delete the "EFI - PARTO" partition:

diskutil  eraseVolume  free  none  disk0s4

Now re-check the drive layout....hopefully you will see a single "(free space)" item that has increased in size by 524.3MB to about 107.6GB.

diskutil  list  internal

If so, then you can merge the "(free space)" item into the "APFS Container disk4" item with current size of 135.0GB with device identifier "disk0s2". The last character is the number zero.

diskutil  ap  resizeContainer  disk0s2  0

If all goes correctly, then you should have the "APFS Container disk4" item with device identifier "disk0s2" with a size of about 242.6GB.

Keep in mind all of these references & device identifiers (including "disk4") are being taken from the screenshot of "diskutil list" in your original post. They may be completely different the next time you boot or reboot the system so make sure to figure out the equivalent device identifiers to use with the commands I presented here.

If something goes wrong it may leave your system where it will not be able to boot.....perhaps it won't even be able to boot into Recovery Mode, then you will likely need to perform a DFU firmware Restore which will erase the internal SSD destroying all data on the internal SSD and it will push a clean copy of macOS onto the internal SSD. The DFU firmware Restore requires access to another Mac running macOS 15.x Sequoia. Afterwards you would need to restore from a backup in order to recover your data.

Before attempting to modify any partitions on the drive, you should make sure you have a good current backup just in case something goes wrong and the macOS partition/Container is damaged or deleted. Modifying partitions and drive layouts is always a risky procedure even when using the Disk Utility GUI app. The Terminal command line has no safety nets and even a simple typographical error can have devastating & unintended results.

For some reason you have 107 GB of “free space.”

Did you partition the drive at some point?

You mention memory when what you mean is storage. Memory is a function of how much RAM you have installed. In a Mac the only reliable way to determine storage is by using Disk Utility. Other methods can show incorrect or variable space.

There isn’t any automated recovery of something you manually set up yourself. You would need to use the partition tab and disk utility to merge your current volume into the rest of the free space.

If you tried to use Boot Camp assistant to make the space, then you should use it to remove the space, but it doesn’t look like it created any sort of a volume to use

You will need to use the command line to merge that "(free space)" back into the APFS Container. Actually you will need to also delete the "EFI - PARTO" partition first since it sits between the "(free space)" and the Containers (deleting it should increase the "(free space)" item. The "(free space)" item then needs to be merged back into what is shown as "Container disk4" with device identifier "disk0s2". I've never tried to do this on an M-series Mac where the system has three necessary Containers.

I will need to locate my notes on the procedure since I did have two people on this forum report success on an Intel Mac.

In the mean time you should make sure you have a good backup because using the command line is always risky especially if you are not familiar with it. There are no safety nets and a simple typographical error can be the difference between success & disaster.

I don’t know how you got it that way, and I don’t know what you can do about it, now.

You're welcome.

Thanks for confirming the instructions were good.