Fix for the XP dual boot problem

[Radu Cornea]

shmuel siegel wrote:
  > I am curious if the following problem is what is meant to be fixed by
> this method. Is it considered safe. I tend to feel that since I can
> currently use both win2k and linux, and they can read each others
> partitions, I should leave everything alone. Especially, since I don't
> have the ability to backup 40g of data. Am I fooling myself and should
> really try to make the disks consistent?
> 
> sfdisk -l /dev/hdb gives
> Disk /dev/hdb: 158816 cylinders, 16 heads, 63 sectors/track
> Warning: extended partition does not start at a cylinder boundary.
> DOS and Linux will interpret the contents differently.
> Units = cylinders of 516096 bytes, blocks of 1024 bytes, counting from 0
>  
>    Device Boot Start     End   #cyls    #blocks   Id  System
> /dev/hdb1   *      0+  40640-  40641-  20482843+   7  HPFS/NTFS
>                 end: (c,h,s) expected (1023,15,63) found (1023,254,63)
> /dev/hdb2      40640+  81281-  40641-  20482875   83  Linux
> /dev/hdb3      81281+  97840-  16560-   8345767+   7  HPFS/NTFS
>                 start: (c,h,s) expected (1023,15,63) found (1023,0,1)
> /dev/hdb4      97840+ 158801-  60961-  30724312+   f  W95 Ext'd (LBA)
>                 start: (c,h,s) expected (1023,15,63) found (1023,0,1)
> /dev/hdb5      97840+ 158801-  60961-  30724281    b  W95 FAT32
>                 start: (c,h,s) expected (1023,15,63) found (1023,1,1)
> 
> running sfdisk -d /dev/hdb gives
> Warning: extended partition does not start at a cylinder boundary.
> DOS and Linux will interpret the contents differently.
> # partition table of /dev/hdb
> unit: sectors
>  
> /dev/hdb1 : start=       63, size= 40965687, Id= 7, bootable
> /dev/hdb2 : start= 40965750, size= 40965750, Id=83
> /dev/hdb3 : start= 81931500, size= 16691535, Id= 7
> /dev/hdb4 : start= 98623035, size= 61448625, Id= f
> /dev/hdb5 : start= 98623098, size= 61448562, Id= b
> 

I am not sure if it is the same problem, but you may try

sfdisk -l -H255 /dev/hdb

and see if the warnings are still there. Your initial geometry probably 
was 255 heads, from the (1023,254,63) on hdb1.
Anyway, if you can boot into win2k you should be fine. It is just the 
2.6 kernel which in some cases does not report the correct disk geometry.

--
Radu