SOLVED: Installer won't see existing windows partitions

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kirgan
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SOLVED: Installer won't see existing windows partitions

Post by kirgan » Thu Dec 11, 2014 4:48 pm

Trying to install Linux mint 17 on a Toshiba Z30 laptop with a solid state drive. Drive was blank (no partitions). I installed Windows 10 (preview), it created the typical two partitions - one NTFS for the OS and one recovery. Windows 10 boots fine.

I then try to install LInux Mint and the installer doesn't even see the Windows partitions - it says the whole 256GB drive is free (no partitions present). I go to a command prompt and run fdisk and it sees the existing partitions just fine. I rebooted to make sure the partitions were still ok and yes it still boots into Windows 10 just fine. So what gives? Why doesn't the Linux Mint installer see the partitions? I haven't been able to do the install yet, since the installer will probably end up wiping or somehow interfering with the existing partitions, since it cant see them.

I wouldn't think the fact that the OS on it now is Windows 10. It uses the same NTFS type partitions as I saw with Windows 7 and Windows 8. I do have another Z30 that has Windows 10 and Linux Mint 17 both on the same drive and that install is working fine. The only difference, is that I believe it had Windows 7 first, that I then upgraded to Windows 10, then I did the Linux Mint install. I could try installing Windows 7 again first and then upgrade like before, but I don't understand why that would work with them using the same partition types.

BTW, I also tried doing this in reverse. I installed linux Mint first and then I was going to install Windows 10 - knowing that I would have to re-install grub afterwards, but Windows 10 complained it could not install on the free space (that I left at the beginning of the hard drive), because this free space was of type GPT.

Any thoughts on why the installer can't see the existing windows partitions, when fdisk can? And any ideas on how to resolve this?
Last edited by kirgan on Sat Dec 13, 2014 5:02 pm, edited 1 time in total.

mintybits
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Re: Installer won't see existing windows partitions

Post by mintybits » Fri Dec 12, 2014 5:20 am

Would you post the outputs of

Code: Select all

sudo fdisk -l
sudo parted -l
sudo blkid

kirgan
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Re: Installer won't see existing windows partitions

Post by kirgan » Fri Dec 12, 2014 3:50 pm

Thanks for the reply. I will post the output of your commands later this evening. I have been troubleshooting this a bit before I read your reply and it seems there must be something wrong with the partition table and I may have to copy off my data on the windows partitions, blow the whole thing away and start over. Besides the obvious issue of the installer not able to see the windows partitions, I came to this conclusion after re-running fdisk and although fdisk can see the windows partition, it does warn me that it is a gpt partition, which is not supported by the fdisk tool, so use gparted instead. I then used the gparted tool. It only sees it as one large drive - all unused, but it complains saying that this drive contains gpt signatures, but no fake msdos partition.

Anyway, thanks again for the help. I will post the output you asked for later this evening.


--Mike

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gold_finger
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Re: Installer won't see existing windows partitions

Post by gold_finger » Fri Dec 12, 2014 5:31 pm

kirgan wrote:I then try to install LInux Mint and the installer doesn't even see the Windows partitions
See these two links to fix problem:

http://www.rodsbooks.com/missing-parts/index.html

http://www.rodsbooks.com/fixparts/
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kirgan
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Re: Installer won't see existing windows partitions

Post by kirgan » Fri Dec 12, 2014 11:58 pm

mintybits,

Here is the output of the requested commands:

sudo fdisk /dev/sda -l

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.

Disk /dev/sda: 256.1 GB, 256060514304 bytes
255 heads, 63 sectors/track, 31130 cylinders, total 500118192 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x1dfd3e54

Device Boot Start End Blocks Id System
/dev/sda1 * 2048 718847 358400 7 HPFS/NTFS/exFAT
/dev/sda2 718848 125831167 62556160 7 HPFS/NTFS/exFAT

sudo parted -l
Warning: /dev/sda contains GPT signatures, indicating that it has a GPT table.
However, it does not have a valid fake msdos partition table, as it should.
Perhaps it was corrupted -- possibly by a program that doesn't understand GPT
partition tables. Or perhaps you deleted the GPT table, and are now using an
msdos partition table. Is this a GPT partition table?
Yes/No? ^C
Model: ATA SAMSUNG MZMTE256 (scsi)
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags


Model: USB DISK 2.0 (scsi)
Disk /dev/sdb: 15.5GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 4129kB 15.5GB 15.5GB primary fat32 boot, lba

sudo blkid
/dev/sda1: LABEL="System Reserved" UUID="60F64BB7F64B8C6A" TYPE="ntfs"
/dev/sda2: UUID="76B054BBB0548391" TYPE="ntfs"
/dev/loop0: TYPE="squashfs"
/dev/sdb1: LABEL="USB DISK" UUID="AC93-8A06" TYPE="vfat"

kirgan
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Re: Installer won't see existing windows partitions

Post by kirgan » Sat Dec 13, 2014 12:00 am

gold_finger,

Thanks for the links. I will read through them and see if that solution works. I will add solved to the subject if it does.

mintybits
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Re: Installer won't see existing windows partitions

Post by mintybits » Sat Dec 13, 2014 4:55 am

The problem is that your disk has both an MS-DOS partition table and a GPT partition table, although the latter has no partitions listed. This is an invalid situation. The MInt installer sees the GPT table and ignores the other table, which is a defect, and stupidly tells you the disk is blank. Fdisk, on the other hand, doesn't support GPT (still!), but reports the MS-DOS table and warns of the presence of a GPT.

Your Windows 10 is using the MS-DOS PT. You need to delete the GPT. To do this, use these commands from a terminal:

Code: Select all

sudo dd if=/dev/zero bs=512 count=1 seek=1 of=/dev/sda
sudo dd if=/dev/zero bs=512 seek=500118191 of=/dev/sda

kirgan
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Re: SOLVED: Installer won't see existing windows partitions

Post by kirgan » Sat Dec 13, 2014 5:10 pm

Gold_finger and Mintybits,

My drive did indeed have a msdos partition and leftover gtp partition info. It looks like you both posted valid and good solutions to my problem. Everything is now working for me with both operating systems installed that I needed Thanks for your help.

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