[SOLVED] My Debian 7 Installation created more than 4 Primary partitions on my MBR disk!!!

Hi

I am very suprised! I previously had a Windows 7 desktop, dual boot with Windows Server 2012 R2. I didn't care much about 2012 R2, so I went with a Debian server on another computer.

I wanted to triple boot my computer, so I looked at my BIOS to see if my computer has UEFI support, but it doesnt, so I am not able to boot to GPT. One decision lead to another, and I decided not to install Hackintosh. As part of this process, I had converted it to GPT, and then back to MBR when installing Windows 8.1 Pro. Everything went well.

When I went to install Debian 7, it was not recognizing anything on that drive. I found out it was a backup GUID partition table left over. I used fixparts found on rodsbooks.com, and I fixed the disk partition table.

Now this is where things get weird. Before installing, I created a primary partition for /, and an extended partition with 5 logical partitions inside it. I installed Debian 7 from a live install DVD, and I manually created the partitions. I created a 4GB /, 16GB /usr, 4GB /var, and 64GB /home. Then I left a bunch of free space (~145GB) and then 16GB swap space. (I have 8GB ram, and I plan to hibernate sometimes).

After a successful installation, installation of packages, reboots, and frustration with PCI card problems, I rebooted to Windows 8.1.

Upon opening diskpart gui, I was greeted with the picture attached.

WHAT IS GOING ON?

Your system is using extended partitions.
https://en.wikipedia.org/wiki/Extended_boot_record

GPT can be used with non-EFI booting as long as you have a BIOS boot partition (type EF02).
https://en.wikipedia.org/wiki/BIOS_boot_partition

and microsoft windows will NEVER know anything about a NON NFTS or FAT partition

the Windows os will never be able to read ext3 or 4 partitions

use Gparted to look at partitions
or the linux command

su -
fdisk -l

Originally Posted by Head_on_a_Stick Your system is using extended partitions. https://en.wikipedia.org/wiki/Extended_boot_record GPT can be used with non-EFI booting as long as you have a BIOS boot partition (type EF02). https://en.wikipedia.org/wiki/BIOS_boot_partition

Let me see if I understand correctly.

I have a BIOS boot partition, so that my BIOS can boot the disk. Windows 8.1 sees this as an MBR partition table and doesn't complain that I don't have UEFI support. However, after the BIOS boot partition, I have a GPT which my bootloader uses.

I don't understand 2 things:
1) Why are those partitions showing up as primary partitions if I am using extended partitions?
2) If Windows 8.1 is using the GPT to find those partitions, how come it is not complaining it needs UEFI support?

Thanks for the links.

Originally Posted by John VV and microsoft windows will NEVER know anything about a NON NFTS or FAT partition the Windows os will never be able to read ext3 or 4 partitions use Gparted to look at partitions or the linux command su - fdisk -l

Are you saying Windows will never detect my Linux ext4 partitions being anything other than unformatted? I knew that, for some reason I decided to open up Diskpart gui and take a peek. I wasn't planning on re-sizing. (Are you subtly hinting I should?)

Thanks for the reply

Newer releases of windows should show Linux partitions as primary or logical and sometimes refer to them as 'healthy', whatever that means. A default windows install will not be able to identify a Linux filesystem type nor will you be able to read/write to them without installing some type of third party software.

Originally Posted by /dev/dog I have a BIOS boot partition, so that my BIOS can boot the disk. Windows 8.1 sees this as an MBR partition table and doesn't complain that I don't have UEFI support. However, after the BIOS boot partition, I have a GPT which my bootloader uses.

No, you have an MBR disk using extended partitions but Windows is calling them all "primary partitions" to try and "help" you (!) -- you can only have one type of partition table.

This is what happens when you rely on "friendly" GUIs -- they obfuscate the true situation.

Boot up Debian and post the output of:

# parted -l

and the truth will be revealed...

Originally Posted by Head_on_a_Stick No, you have an MBR disk using extended partitions but Windows is calling them all "primary partitions" to try and "help" you (!) -- you can only have one type of partition table. This is what happens when you rely on "friendly" GUIs -- they obfuscate the true situation. Boot up Debian and post the output of: # parted -l and the truth will be revealed...

Hey Head on a stick!

Heres the output:

alpha@dogpack05:~$ sudo parted -l
Model: ATA WDC WD5000BPKX-2 (scsi)
Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos

Number  Start   End    Size    Type      File system     Flags
 1      1049kB  368MB  367MB   primary   ntfs            boot
 2      368MB   275GB  275GB   primary   ntfs
 3      275GB   280GB  4295MB  primary   ext4
 4      280GB   500GB  221GB   extended                  lba
 5      280GB   297GB  17.2GB  logical   ext4
 6      297GB   301GB  4295MB  logical   ext4
 7      301GB   370GB  68.7GB  logical   ext4
 8      483GB   500GB  17.2GB  logical   linux-swap(v1)

I see, I knew from a past experience that GUIs are not always transparent, I guess it didn't cross my mind this time.

When you say I have an MBR disk, does that mean I only have an MBR or could it also mean I have a protective MBR, and a GPT right after it? If I do, why did my Debian install create it?
I am just trying to piece together the links you posted. Or did you just post the second link just to clarify that GPT can be used on a non-UEFI machine, given that it has a BIOS Boot partition, and I only have an MBR disk?

Here is a related post in another thread. The OP had a similar problem, and I posted a link to this thread, and I posted the result there of:

$ sudo fdisk -l /dev/sda
$ sudo gdisk -l /dev/sda

gdisk returned that GPT was not present on the disk, only MBR was, so to tentatively answer my own question, I think I only have MBR on my disk.

GPT can be used on non-UEFI machines or on machines which have GPT/UEFI support. If you do not use UEFI, you can still use GPT and it should create a BIOS boot partition. They are usually much smaller, 1MB. A UEFI partition is usually FAT32 and is usually several hundred MB in size.

Your parted output shows 2 ntfs primary partitions, one ext4 primary partition and the 4th primary partition is shown as 'extended' and it contains the logical partitions.

Originally Posted by /dev/dog I only have MBR on my disk.

Correctomundo!

The "Partition Table: msdos" bit tells you that it is an MBR disk.