What is the maximum number of partitions with EFI?

Question

I was wondering what is the maximum number of partition on an GPT-partitionned drive under Linux.

The GPT partition table can contain up to 128 partitions, but the device nodes for /dev/sda? (as described here, block device of major number 8) only allow /dev/sda1 up to /dev/sda15.

Does that means that there cannot be more that 15 partitions on a drive, even on a GPT-partitionned drive?

Answer 1

Well, I think that's where using UUIDs comes in to play. In that case, you don't address a block device as /dev/{h,s}dXY but rather, by the device's UUID. Certainly in that case, the limit would be supremely beyond excess of 128.

Answer 2

No, it means that Linux has a problem. ☺ But we knew that already.

Who told you that the EFI partition table contains up to 128 partitions? That person cannot read specifications. As I've said before, 128 entries of 128 bytes each is the minimum size that is required by the EFI Specification, not the size of an EFI partition table, and certainly not the maximum size.

(Strictly speaking the minimum, first mentioned in version 1.10 of the EFI Specification, is 16KiB total for all partition entries, but not including the header block. With the conventional 128 byte entry length, that's a minimum of 128 entries.)