why 63 ?

[SEVAUX Gence ROSI/DPS DPS]

good morning,

I look for information about linux partitionning, since our storage vendor says 
we can meet disk alignment issues. Now, i begin to understand that, because 
first data partition start on sector 63 and usually the boundaries of tracks, 
stripes are rather a 64 multiplier.

But, for other disk the CHS geometry can be different (for instance 32 sectors 
by tracks). To increase my own knowledge, may you tell me the history of this 
number 63 ?

Best regards,

address@hidden