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I have a compaq laptop with an ide hard drive in it. I try a lot of different OS's and I'm currently switch between Ubuntu, Windows7, and JoliOS(another linux distro). However in Win7 the partition manager reads FIVE primary partitions which I thought wasn't possible. Is this something I should be worried about?


To clarify, I have the linux partitions enclosed in a single logical partition. Screenshot of the same drive from GParted. (booting from the ubuntu partition, not liveCD if that matters)

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Is the disk using MBR or GPT partition table format? (The four-partition limit doesn't apply to GPT, but only computers using EFI can boot from it.) –  grawity Jun 10 '11 at 20:34
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Can you take a screenshot of the partition manager and post it on imgur.com so we can see? –  Mokubai Jun 10 '11 at 20:43
    
Scratch that, I looked in the hardware properties for the HDD and it is indeed MBR. –  Nick Jun 10 '11 at 20:44
    
@Nick: I'm not sure about the GUI partition manager, but if you run list disk in command-line DISKPART, you will see a "Gpt" column. You can also boot from GParted Live CD (or any Linux CD) to manage partitions. –  grawity Jun 10 '11 at 20:45
    
Screen cap: imgur.com/Mv4be –  Nick Jun 10 '11 at 20:47
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3 Answers

up vote 3 down vote accepted

I'm not sure if the comment on your question was a comment from Random or your deleted post but from your second screen-cap you do in fact have an extended partition at the start of your drive that is housing the three Linux partitions, for a total of 3 actual primary partitions.

This is corroborated by the following, though it appears that Linux is enumerating the primary partitions first even though they are located towards the end of the disk.

Device Boot Start End Blocks Id System
/dev/sda1 6536 28220 174183530+ 7 HPFS/NTFS
/dev/sda2 28221 38913 85891522+ c W95 FAT32 (LBA)
/dev/sda3 1 6535 52492356 5 Extended
/dev/sda5 * 1 3246 26073432 83 Linux
/dev/sda6 6015 6535 4184901 82 Linux swap / Solaris
/dev/sda7 3247 6014 22233928+ 83 Linux

Specifically note that the extended partition is at the start of the disk and encloses the Linux partitions (the second and third numbers in the columns are block start and stop numbers).

Windows does not appear to handle this case very well and while it is correctly reporting the positions of the partitions it is not actually showing the extended partition.

Your partition scheme is technically legal and I doubt it will cause any problems, but it is a bit unusual to say the least.

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That's good to hear. I'm no stranger to windows not supporting non-standard formatting so it makes sense that it might not read logical partitions quite the same as linux. A little worried about the logical being listed first despite being at the end maybe causing HDD access delay. Thanks for the help! –  Nick Jun 10 '11 at 21:51
    
Technically I believe Linux is doing it the right way, from what I remember you are supposed to enumerate primary partitions (the two windows partitions) before enumerating extended and logical partitions, it just looks weird to actually see it happen in practice. I don't think it should be causing any real problems or performance drops, and it would be tricky to change it around anyway and as the phrase goes "if it isn't broke, don't fix it" :) –  Mokubai Jun 10 '11 at 21:59
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The 2 other ones are probably the swap partitions created by Ubuntu and Joli OS.

If you want to be sure, give me the command line output of sudo fdisk -l (in Ubuntu or Joli OS).

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Well, the swap partition should be shared between the both. I set up the partitions manually for the two linux installs. Could it be possible that windows is reading the logical partition as three primaries? –  Nick Jun 10 '11 at 21:29
    
Also, the output of fdisk -l: "Device Boot Start End Blocks Id System /dev/sda1 6536 28220 174183530+ 7 HPFS/NTFS /dev/sda2 28221 38913 85891522+ c W95 FAT32 (LBA) /dev/sda3 1 6535 52492356 5 Extended /dev/sda5 * 1 3246 26073432 83 Linux /dev/sda6 6015 6535 4184901 82 Linux swap / Solaris /dev/sda7 3247 6014 22233928+ 83 Linux" –  Nick Jun 10 '11 at 21:31
    
I see sda1 (NTFS), sda2 (FAT32), sda3 (Extended), sda5 (Linux), sda6 (Swap), and sda7 (Linux). Wich basically means that there's a partition wich Windows is installed on, an extra FAT32 partition, 2 partitions with a Linux distro on, and a shared swap partition for the Linux distro's. Do you know what the FAT32 one is? If you don't, then it may be a recovery partition from the manufacturer. –  RobinJ Jun 11 '11 at 17:34
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It is mostly a problem with windows partition manager. It shows the unrecognized(such as ext4 and swap..)) file system as primary even they are not. I guess it will show correctly with Ubuntu any other Linux ver. you installed, or with any other third party partition manager.

Check this also.. http://neosmart.net/forums/showthread.php?t=5818

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