Boot disk volume layout is intricate in Big Sur. M1 Macs lose the EFI partition on their internal SSDs and gain two more for APFS. Contents of /System/Volumes has also changed.
GUID Partition Table
What you need to know about disk formatting using the GUID Partition Table (GPT) to understand its problems and how to repair it.
What do you know about the hidden and unmounted EFI partition on all the disks you use with your Mac? It could be very important.
How does the volume structure differ between Fusion Drives in HFS+ and APFS formats? Does Disk Utility show an accurate picture?
I’ve got two volumes showing in the Finder. So how come diskutil list tells me I’ve got four disks with a total of 12 partitions?
They’re almost everywhere now: UUIDs and GUIDs identify disk volumes, printers, even the processes running on your Mac. Here’s an explanation.