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I've been trying to install Linux as a dual boot with Windows 7 on my Dell latitude e6510. It is currently running Windows 7 and I have used the MS disk tools to shrink the Win 7 NTFS partition to make room for Linux.

The issue I'm having is that when I run Linux installers by boot from CD they see the entire hard drive as unallocated space. I have tried Ubuntu 10.10, Kbuntu 10.10 and Fedora 14 and they all have the same problem.

I have also tried the Ubuntu "install in Windows" option and could not get it to work.

EDIT:

Booting Gparted 0.8.0 from a usb drive did not work. It reported the entire drive as unpartitioned.

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migrated from serverfault.com Mar 7 '11 at 21:08

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4 Answers 4

Try running a gparted boot disk (or USB drive).

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Tried this and had the same problem. Even ran the data recovery, it found an NTFS partition but reported it as being 0 bytes and could not mount it. –  Nash0 Mar 8 '11 at 4:45

Windows 7 uses a "new" proprietary approach on managing hard disks, Dynamic Disk (DD). This new system is a simulation of RAID (so not new at all) plus some other gadgets most normal users will never understand the use of. One of the differences involved is the use of a different partition description block scheme from the standard MBR, the so called Microsoft GPT. In other words, the disk's index introduced by Microsoft differs substancially from that used by the MBR standard. Consequence of this is no other than Microsoft's tools can recognise and correctly understand where the partitions are located and what kind of they are.

Since Linux disk partitioning tools work on the standard MBR system (as most if not all other operating systems), they cannot interpret Microsoft's DD and its GPT' s index. Consequence of this is that a DD partitioned disk is recognised as free as there is no MBR descriptor data. Only to give a chance to recover documents and other files from DD partitions, some additions have been made to the Linux kernel already, to enable it to deal with such hard disk zones. AFAIK further compatibility code is in the way.
Therefore don't forget that Linux doesn't need to continuously try to become compatible with Microsoft's nonstandards...

For the moment, to have Linux dualbooting, you have to force Windows to use the MBR standard and not the Microsoft's own DD. The Linux partitioning tools can then recognize the present Windows MBR partitions and are then able to correctly install Linux and the boot code (GRUB...) for dualbooting. Therefore this strategy is mostly valid if Windows 7 has been already installed this way.

Beware of a suspicious possible risky situation! If you have multiple hard disks on your system partitioned with Windows 7 DD in one of the GPT modes, while installing Linux on one HD different from the first one (C: on Windows), you may be successful on having dualbooting. The problem is that Windows 7, depending on how you have configured your hard disks, may detect a volume failure if such a volume is spanned over the physical HD now used by Linux. You may loose much Windows data this way. Fact is the entire volume, so not only the part physically contained by the said hard disk may be lost with all its data.

So the only rule to follow, for now, is a precise planning from Windows 7 of the MBR partition configuration, avoiding this way the use of multi-hard-disk spanned volumes, reserving the space for the Linux installation and then proceeding with the Linux install.

The big problem is the Windows user must become comfortable (!) with the Dynamic Disc system before being able to modify the partitions setup and make the necessary disk space for the Linux installation.

To conclude, the introduction of the Dynamic-Disk system by Microsoft, is not really a techniocal problem for the Linux-Windows coexistance. At the moment the Linux community is working on this Microsoft novelty to save Windows users from screwing-up their Windows systems while trying to install Linux. To have this additional strategy fully working requires Linux partitioning tools to be aware of non standard partitioning schemes. This maybe introduced very soon as it is a simple modification even if different Windows partition structures may require different approaches to reach a correct setup for the new operating system coexistent installation.

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Interesting. I recently did that twice, on two different machines, without any such problems. But then I used the gparted tool to initially shrink the partitions.

Try booting from a live distro, such as Gentoo LiveDVD, and run fdisk -l /dev/sda and see what that tells you.

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up vote 1 down vote accepted

It turns out my laptop somehow was given two partition tables an MBR and a GPT, which confused Gparted. The Ubuntu and Fedora installers use Gparted to prepare the drive for installation.

Clearing the GPT with Gdisk for windows fixed the situation. Both Windows and Gparted can read my drive now.

http://sourceforge.net/projects/gptfdisk/

http://www.rodsbooks.com/gdisk/gdisk.html

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