Geometry

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B00ze
Posts: 37
Joined: Tue Jul 14, 2015 11:05 pm

Geometry

Post by B00ze »

Good day.

Today's questions are related to the handling of drive geometry by IFW. I know, nothing uses geometry anymore, but I am still worried about it. PS: Why is BBCode disabled? I had to edit the tables below because [code][/code] doesn't work :-(

First question:

Geometry is set to the standard "too big" value of 1023/254/63 for most of my partitions, which is normal since even maximum C*H*S is below the LBA values for the partitions, so we end-up with the industry standard. However, I have noticed that sometimes IFW will present me with a C value of 1022 instead of 1023. Even PartInfo shows this:

MBR Partition Information (HD0 - 0x1B40FA96)
(CHS: 1022/254/63) (WCHS: 38913/255/63)
+====+====+=============+====+=============+=============+=============+
| 0: | 00 | 0000 032 33 | 27 | 1023 254 63 | 2048 | 33554432 |
| 1: | 80 | 1023 254 63 | 07 | 1023 254 63 | 33556480 | 409600 |
| 2: | 00 | 1023 254 63 | 07 | 1023 254 63 | 33966080 | 127815680 |
| 3: | 00 | 1023 254 63 | 07 | 1023 254 63 | 161781760 | 463357952 |
+====+====+=============+====+=============+=============+=============+

As you can see, most of the "C" values are at maximum 1023, but see above the partition listing, in the header of the table -> (CHS: 1022/254/63). Shouldn't this be 1023/254/63? I see 1022 also in IFW: If I select to make a backup in IFW, and in the partition selection screen I highlight partition 2 and click "Information" button, it shows CHS as 1022/254/63; the same "bug" appears in Geometry settings when restoring the partition, 1022/254/63. So why am I seeing 1022 here and there, and not 1023?

Second question:

Here is my partition table AFTER a restore (of partition 2):

+====+====+=============+====+=============+=============+=============+
| 0: | 00 | 0000 032 33 | 27 | 1023 254 63 | 2048 | 33554432 |
| 1: | 80 | 1023 254 63 | 07 | 1023 254 63 | 33556480 | 409600 |
| 2: | 00 | 1023 074 09 | 07 | 1023 254 63 | 33966080 | 127815680 |
| 3: | 00 | 1023 254 63 | 07 | 1023 254 63 | 161781760 | 463357952 |
+====+====+=============+====+=============+=============+=============+

As you can see, according to CHS, Partition 2 now starts BEFORE partition 1 ends. What is IFW trying to accomplish here? I've tried all variations of settings in IFW, I CANNOT get it to stop messing about with geometry; it refuses to restore the starting CHS to 1023/254/63 - So I am curious as to what we are trying to do here with 1023/74/9...

Thank you.
Best Regards,
TeraByte Support
Posts: 3596
Joined: Thu May 05, 2011 10:37 pm

Re: Geometry

Post by TeraByte Support »

some BIOSes use 1023 some 1022, it really doesn't matter since that is used
by old OSes that use CHS to boot and you're not going to be able to access
data beyond that limit anyway.

"B00ze" wrote in message news:10474@public.image...

Good day.

Today's questions are related to the handling of drive geometry by IFW. I
know, nothing uses geometry anymore, but I am still worried about it. PS:
Why is BBCode disabled? I had to edit the tables below because
doesn't work :-(

First question:

Geometry is set to the standard "too big" value of 1023/254/63 for most of
my partitions, which is normal since even maximum C*H*S is below the LBA
values for the partitions, so we end-up with the industry standard. However,
I have noticed that sometimes IFW will present me with a C value of 1022
instead of 1023. Even PartInfo shows this:

MBR Partition Information (HD0 - 0x1B40FA96)
(CHS: 1022/254/63) (WCHS: 38913/255/63)
+====+====+=============+====+=============+=============+=============+
| 0: | 00 | 0000 032 33 | 27 | 1023 254 63 | 2048 | 33554432 |
| 1: | 80 | 1023 254 63 | 07 | 1023 254 63 | 33556480 | 409600 |
| 2: | 00 | 1023 254 63 | 07 | 1023 254 63 | 33966080 | 127815680 |
| 3: | 00 | 1023 254 63 | 07 | 1023 254 63 | 161781760 | 463357952 |
+====+====+=============+====+=============+=============+=============+

As you can see, most of the "C" values are at maximum 1023, but see above
the partition listing, in the header of the table -> (CHS: 1022/254/63).
Shouldn't this be 1023/254/63? I see 1022 also in IFW: If I select to make a
backup in IFW, and in the partition selection screen I highlight partition 2
and click "Information" button, it shows CHS as 1022/254/63; the same "bug"
appears in Geometry settings when restoring the partition, 1022/254/63. So
why am I seeing 1022 here and there, and not 1023?

Second question:

Here is my partition table AFTER a restore (of partition 2):

+====+====+=============+====+=============+=============+=============+
| 0: | 00 | 0000 032 33 | 27 | 1023 254 63 | 2048 | 33554432 |
| 1: | 80 | 1023 254 63 | 07 | 1023 254 63 | 33556480 | 409600 |
| 2: | 00 | 1023 074 09 | 07 | 1023 254 63 | 33966080 | 127815680 |
| 3: | 00 | 1023 254 63 | 07 | 1023 254 63 | 161781760 | 463357952 |
+====+====+=============+====+=============+=============+=============+

As you can see, according to CHS, Partition 2 now starts BEFORE partition 1
ends. What is IFW trying to accomplish here? I've tried all variations of
settings in IFW, I CANNOT get it to stop messing about with geometry; it
refuses to restore the starting CHS to 1023/254/63 - So I am curious as to
what we are trying to do here with 1023/74/9...

Thank you.
Best Regards,

B00ze
Posts: 37
Joined: Tue Jul 14, 2015 11:05 pm

Re: Geometry

Post by B00ze »

> some BIOSes use 1023 some 1022, it really doesn't matter since that is used
> by old OSes that use CHS to boot and you're not going to be able to access
> data beyond that limit anyway.

Good day.

Oh, I know it doesn't matter, I'm of the opinion that all those geometry settings be scrapped from Image, they are useless. But I still find it strange that sometimes, IFW says I have 1022 cylinders, and sometimes it says I have 1023. And what about the 1023/74/9 value that IFW sets when I restore a partition; where does that come from?

Thank you.
Best Regards,
TeraByte Support
Posts: 3596
Joined: Thu May 05, 2011 10:37 pm

Re: Geometry

Post by TeraByte Support »

Your BIOS or Windows environment.

"B00ze" wrote in message news:10484@public.image...

> some BIOSes use 1023 some 1022, it really doesn't matter since that is
> used
> by old OSes that use CHS to boot and you're not going to be able to access
> data beyond that limit anyway.

Good day.

Oh, I know it doesn't matter, I'm of the opinion that all those geometry
settings be scrapped from Image, they are useless. But I still find it
strange that sometimes, IFW says I have 1022 cylinders, and sometimes it
says I have 1023. And what about the 1023/74/9 value that IFW sets when I
restore a partition; where does that come from?

Thank you.
Best Regards,

B00ze
Posts: 37
Joined: Tue Jul 14, 2015 11:05 pm

Re: Geometry

Post by B00ze »

Lol, I see!
Alright, I'm worrying for no reason ;-)
Thanks for the answers tho!
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