Displaying 6 results from an estimated 6 matches for "iso_size".
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2015 Feb 19
0
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
...ower
than 1GiB), the suggested zero-padding would result in the very minimal
size, for any/every size of the ISO image.
Let's repeat the background calculation (please do not interpret the
following pseudo-code as actual functions / operations in C, it is
not):
Cylinders=
trunc(roundup( ISO_size / (Heads * Sectors_per_track * 512))
where 'ISO_size' is the size, in bytes, of the input ISO image.
(Note: roundup(n.0) = n)
So, depending on the potential set of values (ISO_size, Heads,
Sectors_per_track) the minimum amount of Cylinders might need to be
some "i" value, or...
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 20
0
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
...or two). For this example, let's assume:
-h 255
-s 63
ISO size: 1'085'736'960 bytes ( > 1GiB)
This size happens to be a multiple of:
63, 255 and 2048
So, using these values in my suggested loop.
1_ Calculate a potential Cylinders (amount) value;
Cylinders=
trunc(roundup( ISO_size / (Heads * Sectors_per_track * 512))
Cylinders (1st attempt)=
trunc(roundup(1085736960/(255*63*512))
Cylinders (1st attempt)=
trunc(roundup(132))
Cylinders (1st attempt)=132
2_ Calculate 'Cylinders * Heads * Sectors_per_track';
132 * 255 * 63 = 2120580
3._ Is the result of the c...
2015 Feb 19
2
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
Hi,
> Hopefully I am explaining it better this time.
Our ideas of implementation are supposed to yield the
same result.
As said, i am willing to implement my proposal in
a copy of isohybrid.c, if somebody wants to test it.
Advantages and disadvantages should be obvious.
Interested users please send util/isohybrid.c from
your local SYSLINUX source code installation to me.
Just to be sure
2015 Feb 18
0
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
...considered
unacceptable by some users.
So, instead of immediately making such a big jump (in the resulting
size), I am suggesting to repeat (loop) the calculation (please do not
interpret the following pseudo-code as actual functions / operations in
C, it is not):
Cylinders=
trunc(roundup( ISO_size / (Heads * Sectors_per_track * 512))
where 'ISO_size' is the size, in bytes, of the input ISO image.
(Note: roundup(n.0) = n)
With this first-attempt value, calculate the potential resulting
isohybrid image size. Is it a multiple of 2048 bytes?
If the potential resulting isohybrid ima...
2015 Feb 18
3
isohybrid and ISO images whose size is not a multiple of 2048 bytes vs. VirtualBox
Hi,
it would be interesting to know for what solution
TAILS decides and whether any problems arise with it.
-------------------------------------------------------
On with the fundamental discussion of MBR cylinders:
Ady wrote:
> 1_ The resulting ISO9660 file system size shall be a multiple of 2048
> (bytes_per_sector).
The known ISO production programs comply to this condition.