Bug 688652

Description of problem:
- /dev/sda1 starts on sector 1 on EC2 AMIs

Version-Release number of selected component (if applicable):
RHEL5.5 EC2 AMIs

How reproducible:
100%

Steps to Reproduce:
1. Build an image from http://cvs.devel.redhat.com/cgi-bin/cvsweb.cgi/utility-scripts/cloud/kickstarts/rhel5-x86_64-AMAZON-STARTER.ks?rev=1.1;content-type=text%2Fplain;cvsroot=RH-RelEng;f=h
2. Boot it
3. sfdisk -uS /dev/sda|grep sda1
  
Actual results:
/dev/sda1 : start=        1, size=..., Id=83

Expected results:
/dev/sda1 : start=       12, size=..., Id=83

Additional info:

- The space after the MBR in the first track is usually used by grub for stage1.5, which we don't need with EC2

- This breaks fdisk badly if one tries to grow the partition by deleting it and recreating it larger (with a bigger size):

Command (m for help): u
Changing display/entry units to sectors

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First sector (63-209715199, default 63): 1
Value out of range.
First sector (63-209715199, default 63): 

- I believe this might break block alignment between the ext filesystem and underlying storage if Amazon ever switches to 4KB storage blocks (more and more common), causing a very significant performance drop.

- More importantly, if one does not change the unit size in fdisk and "carelessly" keeps the starting position of 1, as appearing in the fdisk -l output and commonly used since the dawn of ages on IBM PC, the system will not boot anymore.