new@luna:~/Desktop/temp/laptop-image-config1$ cat /proc/partitions
major minor  #blocks  name

   3     0  156290904 hda
   3     1   39062016 hda1
   3     2  115234245 hda2
   3     3    1992060 hda3
   3    64  117220824 hdb
   3    65  117218241 hdb1
 253     0   39062016 dm-0
 253     1  115234245 dm-1
 253     2    1992060 dm-2
 253     3  117218241 dm-3
 253     4   78180291 dm-4
   8    16   78184008 sdb
   8    17   78180291 sdb1
new@luna:~/Desktop/temp/laptop-image-config1$ sudo sfdisk -d /dev/hda
# partition table of /dev/hda
unit: sectors

/dev/hda1 : start=        0, size=        0, Id= 0
/dev/hda2 : start=        0, size=        0, Id= 0
/dev/hda3 : start=        0, size=        0, Id= 0
/dev/hda4 : start=        0, size=        0, Id= 0
new@luna:~/Desktop/temp/laptop-image-config1$

******** formula *********
jelly-home> so run bc
<jelly-home> scale=4
<jelly-home> 39062016*2
<jelly-home> .+63
<jelly-home> ./63
<jelly-home> (... is an integer, good)
<jelly-home> ./255
<jelly-home> (should be an integer too)
<jelly-home> this is the size of the partition in cylinders



*********** calculations ******************
hda1 39062016 -> 4863.0000  (with +63 offset)
hda2 115234245 -> 14346.0000 (without offset)
hda3 1992060 -> 248.0000  (probably swap area) (without offset)