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**perspectoff** · May 14, 2012, 05:49 PM

Question 1:

Windows 7/8 sometimes boots from a single (primary) partition and sometimes uses two (primary) partitions (an OS partititon and a boot partition). Which does your Windows system do?

It seems from your description that there is a single Windows partition...

I personally am a fan of having 3 primary "DOS" partitions and one extended "DOS" partition. All Linux partitions (including the SWAP partition) would be contained as "logical" partitions within the "extended" partition.

I you are only using one partition for Windows, then keep primary partitions 2 and 3 as "placeholders" (they can be a nominal 20 Mb or 50 Mb if you choose) for later use. (I happen to use one of those primary partitions as a "boot" partition in which I place a standalone Grub Legacy bootloader (for which I like the standalone Grub Legacy) but that isn't strictly necessary.) I tend to put all my Linux partitions within the fourth "extended" DOS partition, since it is the most flexible.

By doing this, you don't have to worry about whether Windows boots from one partition or two, since you will be using Linux only from the FOURTH partition. Within the fourth extended partition should be a single 2 Gb Linux-swap logical partition (any other size is a waste) and then one logical partition for each Linux OS yo9u will install. You can have as many logical partitions as you want within the extended partition, which is why it is so flexible.

Question 2:

DO NOT format the entire drive. You will erase your Windows partition if you do so... why do that?

**james147** · May 14, 2012, 05:50 PM

Whats the output of sudo parted -l print?

**james147** · May 14, 2012, 05:51 PM

Originally posted by perspectoff View Post

I you are only using one partition for Windows, then keep primary partitions 2 and 3 as "placeholders" (they can be 20 Mb or 50 Mb if you choose) for later use. (I happen to use one of those primary partitions as a "boot" partition in which I place a bootloader (for which I like the standalone Grub Legacy) but that isn't strictly necessary.) I tend to put all my Linux partitions within the fourth "extended" DOS partition, since it is the most flexible.

Is there any real need to create place holder primary partitions? I see no reason for them. You can always have upto 4 primary partitions you just need to resize the others to give the space you need for them when/if you need them.

**perspectoff** · May 14, 2012, 05:58 PM

Yeah. If a user contantly re-arranges partitions (like I do), they will be renumbered. By creating 4 partitions and keeping placeholders, they will not be renumbered. If you've never had your partitions renumbered or UUIDs changed while re-arranging them, then you have been lucky (or haven't actually done it much). There is a benefit to always having 4 partitions and keeping the partitions consistently numbered and identified, IMO. Furthermore, on a 1.5 Tb drive, having two placeholders of 50 Mb each will not even be noticed.

Believe me, I've experienced every screw up Grub2 can throw at me.

**james147** · May 14, 2012, 06:15 PM

Originally posted by perspectoff View Post

Yeah. If a user contantly re-arranges partitions (like I do), they will be renumbered. By creating 4 partitions and keeping placeholders, they will not be renumbered. If you've never had your partitions rebumbered or UUIDs changed, then you have been lucky.

UUIDs are set when you format a drive (create the file system on it) they will NEVER change when changing partitions around... otherwise they would be completely useless.

Partition numbers are assigned when the partition is created and also will not change unless you delete or recreate that partition (not just the file system). fdisk even has a function to change the partition numbers should you want to renumber them as it does not happen when you move or extend partitions.

The drive letter is another matter, the drive letters are assigned at boot and depend on the order the drives are connected or what ports the drives are connected to (at least in most cases) but the actualy partition number does not change.

Using fdisk:

Code:

[B]% ls /dev/sde* #My external usb drive
[/B]/dev/sde  /dev/sde1  /dev/sde2
[B]% # Used fdisk to delete partition 1
[/B][B]% ls /dev/sde*[/B]
/dev/sde  /dev/sde2
[B]% # Used fdisk to recreate partition 1 and create partition 4 notice how I don't even need to create a partition 3
[/B][B]% ls /dev/sde*[/B]
/dev/sde  /dev/sde1  /dev/sde2  /dev/sde4

Using KDE partition manager:

Code:

[B]% ls /dev/sde*
[/B]/dev/sde  /dev/sde1  /dev/sde2
[B]% # Deleted partition 1 using KDE partition manager GUI[/B]
[B]% ls /dev/sde*
[/B]/dev/sde  /dev/sde2
[B]% # Moved partition 2 to the front of the disk
[/B][B]% ls /dev/sde*
[/B]/dev/sde  /dev/sde2
[B]% # Created partition 1 (physically located after partition 2)
[/B][B]% ls /dev/sde*[/B]
/dev/sde  /dev/sde1  /dev/sde2
[B]% # Moved partition 1 to the end of the drive and created partitions 3 and 4
% ls /dev/sde*
[/B]/dev/sde  /dev/sde1  /dev/sde2  /dev/sde3  /dev/sde4
[B]% # Deleted partitions 1 and 3
[/B][B]% ls /dev/sde*[/B]
/dev/sde  /dev/sde2  /dev/sde4
[B]% # Unplugged the drive and plugged it back in again
[/B][B]% ls /dev/sde*[/B]
/dev/sde  /dev/sde2  /dev/sde4

**SteveRiley** · May 15, 2012, 12:23 AM

And GPT eliminates the need to worry about primary/extended MBR partitions. Alas, Windows will install to GPT only if the computer has UEFI; if it's BIOS, Windows requires MBR. Sigh. Linux, of course, doesn't incorporate such arbitrary restrictions.

**oshunluvr** · May 15, 2012, 09:48 AM

With MBR format drives, partition numbers may change, but only if you remove a partition "upstream" from another of the same type (primary or logical). If you add a primary partition after creating logical partitions and re-number the primary partitions, the partition number of your extended partition will change, but you don't address (mount or create a filesystem) the extended partition directly so the change in partition numbering has no net effect in this case.

If you're savvy enough to do this sort of re-arranging of partitions, you're also likely savvy enough to adjust grub when you're done without too much trouble. And as James so deftly pointed out, use UUID's in grub/fstab and none of the above has any effect at all. Of course, if you're still using the decades old grub-legacy or even older lilo, you'll have much more trouble.

The only time I revert to device names for mounting is for partitions I know I will often re-format, thus forcing a UUID change. I might do this for filesystem evaluation and testing, but not for partitions in regular use.

Of course, none of this has anything to do with the OP's problem.

I would suspect the partition table is not being seen properly. I would be curious to know what the motherboard/chipset being used is, what BIOS type and version, how the partitions were created (with what tools), and what a boot to GpartedLive shows.

Have you tried mounting the drive while running from a liveCD or USB?

If the partition table is somehow "bad" it can be recreated with the proper data, but it's not easy for a noob. If windows sees the partition table, it must have some data in it correctly. I reserve further comments for when the OP reports back.

**gdafnas** · Jul 26, 2012, 08:05 AM

Hi!
I am dealing with the exact problem.
I boot from liveCD Kubuntu 12.04 and while the live os can recognize my windows partitions and I can even access it, browse through my window files etc, when I start the installer my disk appears empty and says i got 320GB unallocated space.
There are actually 3 partitions on this disk,
1. system reserved partition for win7
2. my windows partition
3. 100 GB raw space that i kept in order to install kubuntu.

I have tried booting with nodmraid and all_generic_ide options still the same issue.
I have changed to all possible options for sata recognition on BIOS still nothing.

Last thing I got Partition Table Doctor and says "Error: The total sectors of the partition 1 on harddisk 1 is 204800. The right total sectors is 206010. Do you want to correct the error?" I tried that but then windows wouldn't boot. I had to boot to win recovery and repair this, and when I reopened partition table doctor it displayed the same error.

Could this be the problem from which the installer can't see my partitions?
Thank you in advance

PC Config:
Desktop
CPU: q6660 quad core 2.4 cpu
ATI HD6450
6GB RAM
HD: Western Digital wd3200aajs 320GB

**oshunluvr** · Jul 26, 2012, 08:29 AM

A quick search revealed some very negative reviews of that Partition Table Doctor you're using. I would recommend either gParted or PMagic for drive tools.

http://gparted.sourceforge.net/livecd.php
http://partedmagic.com/doku.php?id=downloads

I would hate to give you any advice that might bork your windows install. I would guess that your windows install is using a non-standard NTFS boot record - but that's just a guess. Did you shrink your NTFS partition using the Windows 7 partition tool? My understanding is that is the best way to free up space using Win7.

**gdafnas** · Jul 26, 2012, 02:31 PM

Hello again!

I have finaly found the solution here

http://ubuntuforums.org/showpost.php...49&postcount=9

It appears there was a wrong GPT entry, so i deleted that entry from within PMagic leaving the MBR intact.
After that windows were still able to boot properly and the linux installer was finaly able to read correctly the partitions and continue the installation!

**oshunluvr** · Jul 26, 2012, 03:09 PM

Great job!

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Manual partition installation, can't see my partitions.

Manual partition installation, can't see my partitions.

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