[patel45]

Non ci capisco più nulla, ecco i risultati dei comandi geometry dati dalla shell di Pclos (distro principale):

grub> geometry (hd1)
drive 0x81: C/H/S = 25841/240/63, The number of sectors = 390721968, /dev/sda
   Partition num: 0,  Filesystem type unknown, partition type 0x7
   Partition num: 4,  Filesystem type is ext2fs, partition type 0x83
   Partition num: 5,  Filesystem type is ext2fs, partition type 0x83
   Partition num: 6,  Filesystem type unknown, partition type 0x82
   Partition num: 7,  Filesystem type is ext2fs, partition type 0x83
   Partition num: 8,  Filesystem type is ext2fs, partition type 0x83

grub> geometry (hd0)
drive 0x80: C/H/S = 77557/16/63, The number of sectors = 78177792, /dev/hdd
   Partition num: 0,  Filesystem type unknown, partition type 0x7  (vista)
   Partition num: 4,  Filesystem type unknown, partition type 0x82 (vuota)
   Partition num: 5,  Filesystem type is ext2fs, partition type 0x83 (ubuntu)
   Partition num: 6,  Filesystem type is ext2fs, partition type 0x83 (fedora)

e quelli di fdisk -l

fdisk -l

Disk /dev/hdd: 40.0 GB, 40027029504 bytes
16 heads, 63 sectors/track, 77557 cylinders
Units = cilindri of 1008 * 512 = 516096 bytes

Dispositivo Boot      Start         End      Blocks   Id  System
/dev/hdd1   *           3       40103    20210688    7  HPFS/NTFS
/dev/hdd2           40104       65055    12575808    5  Esteso
/dev/hdd5           40104       42144     1028632+  82  Linux swap / Solaris
/dev/hdd6           42145       52928     5435104+  83  Linux
/dev/hdd7           52929       65055     6111976+  83  Linux

Disk /dev/sda: 200.0 GB, 200049647616 bytes
240 heads, 63 sectors/track, 25841 cylinders
Units = cilindri of 15120 * 512 = 7741440 bytes

Dispositivo Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        2709    20480008+   7  HPFS/NTFS
/dev/sda2            2710       25842   174880913    f  W95 Ext'd (LBA)
/dev/sda5            2710        3522     6146248+  83  Linux
/dev/sda6            3523        4471     7174408+  83  Linux
/dev/sda7            4472        4593      922288+  82  Linux swap / Solaris
/dev/sda8            4594       25008   154337368+  83  Linux
/dev/sda9   *       25009       25842     6300472+  83  Linux
+

il disco sda è quello di boot, ed è sempre stato hd0, ora sembra hd1
se invece il comando geometry lo do direttamente da grub allora l'output va d'accordo con fdisk -l.