Question on what sectors grub2 uses?

[Michael D. Setzer II]

I am the current maintainer of the G4L disk imaging project, and 
long ago added options to backup the basic mbr being the first 
512 bytes of the disk. Later added an option that would backup 
the first track (63 sectors) of the disk to include additional code 
that was being placed there by some OSs. 

In a recent clean install of Fedora 16 I noted that first partition is 
starting at 2048 instead of 63 from previous version. 

What would be the necessary steps to backup the mbr and grub2 
info?

dd if=/dev/sda of=mbrgrub2 bs=512 count=????

Would it be 2048, 2047, or some other number?

I also noticed I had some machines that were upgraded to Fedora 
16, and had the grub2 installed, but it only had 63 sectors for the 
first partition to start which was XP. The grub2-install --recheck 
would report the area is now to small, but it was using the grub2 
boot process, so I assume that one time it did fit with an earlier 
grub2? With a lot of work, I was able to resize and move various 
partitions over and free the space so the first partition started in 
2048 and then the grub2-install --recheck ran with no problems 
and seems to be fine.

My only big problem has been that I did a preupgrade on another 
systems recently to Feora 16, and it went thru fine, but on reboot 
it was still using the older grub instead of the grub2, and it was 
listing the old kernel that didn't exist any longer. Fortuantely, I had 
a kernel from my g4l project that was there, and it allowed me to 
boot and I was able to modify the old grub.conf and get it to boot.
It appears that the preupgrade is not able to install the newer 
grub2 in the 62/63 sectors that were available? The boot partition 
on that machine was 1024M, so I reduced it to 1023M and moved 
it over to free up the space. Then I ran the grub2-install, and it ran 
with no errors, but I have not actually rebooted the machine to test 
it??? 


+----------------------------------------------------------+
  Michael D. Setzer II -  Computer Science Instructor      
  Guam Community College  Computer Center                  
  mailto:address@hidden                            
  mailto:address@hidden
  http://www.guam.net/home/mikes
  Guam - Where America's Day Begins                        
  G4L Disk Imaging Project maintainer 
  http://sourceforge.net/projects/g4l/
+----------------------------------------------------------+

http://setiathome.berkeley.edu (Original)
Number of Seti Units Returned:  19,471
Processing time:  32 years, 290 days, 12 hours, 58 minutes
(Total Hours: 287,489)

address@hidden CREDITS
SETI        11905068.286825   |   EINSTEIN     7462372.579852
ROSETTA      4297236.297156   |   ABC         11575002.495854