Detected hard disk geometry changed after installing FC2T2

[Hervé Pagès]

Hi,


My disk is a Seagate 120 GB, model ST380021A with 8MB of cache.

Depending on the "Access Mode" in use, my BIOS detect the following
geometry :

  o "Access Mode" set on "Auto"     o "Access Mode" set on "LBA"
      Cylinder = 38309                  Cylinder = 9729
      Head = 16                         Head = 255
      Sector = 255                      Sector = 63


1. BEFORE installing FC2test2, I boot in FC1 and I get the following :

    # hdparm -g /dev/hda
     geometry     = 9729/255/63

    # fdisk /dev/hda"
     255 heads, 63 sectors/track, 9729 cyl.

   NB : I get the same result whatever the "Access Mode" is ("Auto"
   or "LBA").


2. DURING install of FC2T2, I get the following warning :

    "Unable to align partition properly. This probably means that another
     partioning tool generated an incorrect partition table, because it
     didn't have the correct BIOS geometry. It is safe to ignore,
     but ignoring may cause (fixable) problems with some boot loaders".

   After that DiskDruid displays a strange partition tables containing
   some small free spaces (< 1 cyl. each) beetween my partitions.

   NB : This happens with both "Access Mode=Auto" and "Access Mode=LBA".
   But this doesn't happen when installing FC1 on the same HD, with the
   same partition table !


3. AFTER installing FC2T2, my disk geometry seems to be different now :

     - If I boot in FC2T2 :

         # hdparm -g /dev/hda
          geometry     = 65535/16/63  (with "Access Mode" set to "Auto"
                                       or to "LBA")

     - If I boot in FC1 :

         # hdparm -g /dev/hda
          geometry     = 155061/16/63 (with "Access Mode" set to "Auto")
          geometry     = 9729/255/63  (with "Access Mode" set to "LBA")

     - With both FC1 and FC2test2, "fdisk /dev/hda" gives :
          16 heads, 63 sectors/track, 155061 cyl.

       And with "fdisk -H 255 /dev/hda", I get :
          255 heads, 63 sectors/track, 9729 cyl.
       But this time, if I print the partition table with "p", I get
       "Partition 1 does not end on cylinder boundary" and the same
       message for partitions 2, 3 and 4.


4. With "Access Mode" set to "Auto", Windows XP (/dev/hda1) doesn't
    boot anymore. (It did boot before installing FC2T2).
    With "Access Mode" set to "LBA", it does boot again.


5. I'm totally confused :-(


Hervé Pagès
pages at inrp.fr