Displaying 3 results from an estimated 3 matches for "number_of_cylind".
2015 Feb 19
0
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
> Hi,
>
> Ady wrote:
> > my suggestion to modify the _amount_ of Cylinders was intended to
> > overcome the "by 4" (or rather, "by 2048") issue.
>
> Now i get your intention. You want to align the
> resulting ISO to 4 full cylinders in order to avoid
> the need for a cylinder size divisible by 4.
>
No :). I want to align to resulting
2015 Feb 19
2
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
Hi,
Ady wrote:
> my suggestion to modify the _amount_ of Cylinders was intended to
> overcome the "by 4" (or rather, "by 2048") issue.
Now i get your intention. You want to align the
resulting ISO to 4 full cylinders in order to avoid
the need for a cylinder size divisible by 4.
This would work. But with -h 255 -s 63 it could waste
up to 32,899,072 bytes.
>
2015 Feb 19
2
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
...d computation does.
It predicts the minimum number of cylinders which you need
as padding target in isohybrid.c (or .in).
Sorry for being sloppy with the natural language description
of the concept. Let me try it more formal:
The size of an image file which is aligned to full
cylinder size is:
number_of_cylinders * h * s * 512
If we divide by 2048 = 2 exp 11, we can cancel
512 = 2 exp 9 and get
number_of_cylinders * h * s / 4
In order to cancel the remaining 4, we need two prime
factors 2 among those of number_of_cylinders, h, and s.
We find at least two 2s in h and s if and only if h * s is
divis...