Formatting EFI internal partition

Make sure to have a good system backup before you do anything as you could make the system unbootable or worse lose access to all the data.

Use Disk Utility to remove the partition. You should always use the tools for the OS that is in control of the drive since other third party tools and operating systems may not know all the secrets the main OS needs for a valid partition.

Depending how you created this partition in the first place you may be unable to merge it back into another Mac partition so you may have no choice but to erase the whole drive and restore from a backup.

Why do you have a 29GB EFI partition? Linux doesn't work from a FAT file system and the Linux bootloader can easily use the main macOS ESP/EFI system partition as Linux will create its own subfolder within the "EFI" folder on that EFI/ESP partition.

For anyone wanting to experiment with Linux I highly recommend using a Virtual Machine or at the very least install Linux to an external drive so their is minimal risk to causing problems to the internal macOS drive. Running Windows in a VM is also preferable to sharing the macOS boot drive.

You should be able to do that from Linux using GParted. You have to boot from the Linux distro. Are you referring to the EFI EFI volume disk0s1 or the EFI volume disk0s2? You also may be able to do it using Disk Utility if you boot from the Recovery HD.

HWTech wrote:

For anyone wanting to experiment with Linux I highly recommend using a Virtual Machine or at the very least install Linux to an external drive so their is minimal risk to causing problems to the internal macOS drive. Running Windows in a VM is also preferable to sharing the macOS boot drive.

Put differently (and to emphasize what HWTech writes), more than a few folks have found issues with partitions can corrupt their installations. This whether due to command errors or software incompatibilities or software errors. Recovery commonly means wiping all partitions, reloading each from backups. Operating with Virtual Machine guests is far more forgiving.