[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: where does grub put the MBR?



Digby Tarvin wrote:
On Thu, May 04, 2006 at 04:16:08PM -0500, Nate Bargmann wrote:

* Alvin Oga <aoga@mail.Linux-Consulting.com> [2006 May 03 07:06 -0500]:


Well the MBR, is always in the same place.  It is *always* the first 512
bytes on the physical disk.

the MBR is the first 446 bytes of each partition ....
	16 bytes for each of the 4 primary partition
	 2 bytes for the boot flag

and if you have more than one partition, the "boot record" is the
first 448 bytes of each primary primary

So, the MBR (first 512 octets) contains the partition information for
up to four primary partitions or one to three primaries and one extended.
Where are succeeding partition (hda5 and higher) records kept for partitions in an extended partition?


In the extended partitions themselves. The extended partition has its
own MBR which contains two partitions entries - one for a logical
partition, and the second for another 'extended partition' which
repeats the process.

[snip]

Sorry to reply so late. There is exactly ONE MBR per disc. The extended
partition does indeed have information about volumes contained in it,
but this does not constitute an MBR.

Otherwise, good information.

Mike
--
p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
This message made from 100% recycled bits.
You have found the bank of Larn.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!



Reply to: