On which partition is the MBR?

[chrstrbrts]

Hi,

When using the old MBR scheme for a hard disk, where is the actual MBR stored?

On what partition?

I ask because apparently, after some inspection, my HD has everything on one huge partition, WIN7 OS, the boot loader, everything.

How can an MBR be on a bootable partition?

That is to ask, how can an MBR be on the same partition as an OS?

The MBR should contain the primary bootloader and a partition table.

The primary bootloader should use the partition table to find a bootable partition and pull the first sector of that partition called the volume boot record (I think) into RAM and run the code there.

That code is basically a second stage bootloader.

Things go on from there.

But the MBR is located on the first sector of the first track of the disk.

I would assume then that the MBR is in the first sector of whatever partition it's on.

So, if the MBR shares a partition with an OS and tries to pull the VBR of that OS into RAM, it should end up pulling itself into RAM and creating some kind of infinite loop.

But this doesn't happen to me.

So what am I missing?

 

[TheELF]

The MBR is on the first sector of the disk as you said and not of the partition,it's outside/before of any partition.

 

[chrstrbrts]

The MBR is on the first sector of the disk as you said and not of the partition,it's outside/before of any partition.

OK, that makes sense.

But why is it that when I open Disk Management in Windows to view my HD, there is no mention of the MBR at all?

It's treated like it's not even there.

 

[mv2devnull]

The MBR is tiny. It does not take many bytes to tabulate partitions (the table in MBR has room for only 4 partitions). It does not take many bytes to have a code that can load actual bootloader/bootmanager from a filesystem (i.e. from partition).

GPT has only the table, albeit larger. The UEFI knows how to find the EFI System Partition and bootloader within.

Disk Management does show, implicitly, the format of the partition table. "MBR", "GPT", "Dynamic disk". Implicitly, as in "I won't tell who I am, but I'll tell who the other two are".