# Disk geometry problem



## petike (Jan 4, 2009)

Hi,
I have tried to install "FreeBSD v7.0" to my computer and before I
got into "FDISK Partition Editor" I had got the following WARNING:

===============================================
_WARNING: A geometry of *155061/16/63* for *ad0* is incorrect (...and about 7 uninteresting lines below it  ...)._
===============================================

By the way, I have only "one 80 GB" hard-disk in computer and I have already Windows XP installed (I want to have two operating systems in computer).

And what now? I have tried to "googling" this problem out but I still don't know what exactly I have to do?
I think that I have to change the disk geometry to the right one but which is "the right one"?
With the program "KillDisk" I have found out that the geometry of my disk is *"155061/16/63"* or if you want:
_  -Cylinders = 155061
  -Tracks per cylinder = 16
  -Sectors per track = 63_
but FreeBSD "thinks" that I have another configuration: *"9729/255/63"*.
And now, what geometry is the right for me, thus which I have to set. Or how can I find out the right disk geometry (I think if it is written in BIOS or elsewhere...)?
Thanks.


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## danger@ (Jan 4, 2009)

please ignore this warning, it's harmless and has been removed in 8.0-CURRENT already.

You might also want to install 7.1-RELEASE (it's already available on the ftp mirrors and torrent site).


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## petike (Jan 4, 2009)

*Veeeeery confused...*

Hi again,
now I am veeeery confused with that "FDISK Partition Editor".

First of all, I will describe my current situation:
=======================================
_I have "one 74 GB" (in my 1st post I was wrong, it's "8 000 000 000 bytes", not "80 GB") hard-disk. I have just Windows XP installed so that I have used "32 GB" for "C:" partition and "30 GB" for "D:" partition, thus there should still be "12 GB" free space left ("74 - 32 - 30 = 12 GB").
And my hard-disk has size of "156 296 385" sectors._
=======================================

But now, in "FDISK Partition Editor" there is written that the previously created "C:" partition has size of "67 103 442" sectors and the "D:" partition has size of "89 176 815" sectors which is a little bit strange because the "C:" partition is bigger than (32 GB > 30 GB) "D:" one but "D:" is bigger "in sectors" (isn't is strange?).

And moreover, it shows me 2 unused partitions: 1st (very small) is reserved for some "partitioning information", that I understand, but the 2nd unused partition has size (in sectors) of "21 168" which is a little bit "little". *Where is that "12 free GB" left*? If "67 103 442" sectors equals something about "30 GB", probably "21 168" sectors doesn't equal something about "12 GB".


And if someone could solve the above problem, there is another one.
In that "FDISK Partition Editor" I can set which partition should be "boot-able" (I can set only one partition as boot-able). Should I set the newly created FreeBSD partition to be boot-able or the "C:" partition (with Windows XP) to be boot-able?

Thanks in advance.


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## graudeejs (Jan 4, 2009)

bios only supports 1 bootable partition per HDD

some space is required for file systems....

It's not possible to use all space on disk unless you use raw space with no fs/partitions etc


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## danger@ (Jan 4, 2009)

It's indeed a bit strange that the c: partition is smaller in sectors than the d: partition, maybe you did a typo while creating them in the windows installer?

BTW 1 sector commonly equals to 512 bytes.

well the 12GB you are looking for won't be there. You can't use the whole capacity of your HDD, it's normal...

As of the bootable partition, leave it as it's now and install a boot loader.


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## petike (Jan 4, 2009)

danger@ said:
			
		

> It's indeed a bit strange that the c: partition is smaller in sectors than the d: partition, maybe you did a typo while creating them in the windows installer?



I have checked it again by Windows XP installer "partitioning tool":

```
C:  Partition [NTFS]               32765 MB
D:  Partition [NTFS]               30718 MB
    Unpartitioned space            [B][color="DarkRed"]12825 MB[/color][/B]
    Unpartitioned space            8 MB
```
so there *IS* a free space of "12825 MB" but "FreeBSD FDISK Partitioning Tool" tells me that I have only about "7 MB" left.
I think that it could be due to the warning (in the 1st post) I have got, couldn't it?



			
				danger@ said:
			
		

> well the 12GB you are looking for won't be there. You can't use the whole capacity of your HDD, it's normal...



It is clear to me that I can't use the "whole" capacity of my hard-disk, probably there are some sectors for "partitioning management", but if I have only "7 MB" left instead of "12 000 MB" (there would then be "almost 12 GB" for partitioning management), it is strange, isn't it?


Any other solutions?
Thanks.


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## graudeejs (Jan 4, 2009)

you know what:
why won't you use sysinstall fdisk?
It's way more easy to use and harder to mess things up.

i use it almost always, unless i'm bored and searching for something few 
in sysinstall fdsik make modifications and press W to write changes to disk, then just exit sysinstall.

It's the easiest, safest way i know
also for sysinstall fdisk you can better see what is partitioned and what is not.

also could it be that tool you used doesn't just recognize partition type or somthing


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## danger@ (Jan 4, 2009)

Okay, what does actually "FDISK Partition Editor" say exactly? Can you post the lines?


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## petike (Jan 4, 2009)

*"What FDISK says"...*



			
				danger@ said:
			
		

> Okay, what does actually "FDISK Partition Editor" say exactly? Can you post the lines?



Before FDISK utility this screen is shown:






And after that follows this one:





Try to look at the blue-marked line: in the 2nd column (size of sector) there is the value "21 168" which is approximately "7 MB". But I have about "12 000 MB" of free space, no just "7 MB".

Other solutions?


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## danger@ (Jan 4, 2009)

ah, well now it's a bit more clear. You have created the d: partition as the extended one. FreeBSD doesn't currently support installing on extended partitions, so you will have to destroy the d: partition and re-create it as a primary partition again.

Hope that helps.


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## petike (Jan 4, 2009)

danger@ said:
			
		

> FreeBSD doesn't currently support installing on extended partitions, so you will have to destroy the d: partition and re-create it as a primary partition again.



But I don't want to install FreeBSD to that extended partition, I have it created for *Windows XP* data.
I want to install FreeBSD to the new *3rd* partition - just after "C:" and "D:" (these are for Windows, not for FreeBSD).

*The main problem remains the same:*
Why do I have so little free space (21 168 sectors)?

Thanks also for your previous posts.


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## danger@ (Jan 4, 2009)

I suppose the extended partition ate the whole free space on your hard drive and you only have these 12gb of free space *in that* extended partition which freebsd does not see.


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## petike (Jan 4, 2009)

danger@ said:
			
		

> I suppose the extended partition ate the whole free space on your hard drive and you only have these 12gb of free space *in that* extended partition which freebsd does not see.



Oh,
I have tried that and now it seems to be OK.

You will *certainly* get my *thanks*.

I will try to install it and I will tell here if I was successful.

Thanks once more.


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## petike (Jan 5, 2009)

*Successfully installed*

I am just confirming that FreeBSD installation have successfully finished without any other problems.

Once more a *BIG THANKS* to all who helped me.
Now I can start "playing" with FreeBSD.

Bye.


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