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I just bought a new hard drive so that I could convert my XP-only machine into an XP-Ubuntu-Windows 7 triple boot machine. Since the drive is absurdly huge (1 TB) I wouldn't mind throwing ReactOS into the mix, too.

I just found out that master boot records are limited to 4 entries, meaning 4 primary partitions. I had Windows XP set up on my old drive as a boot partition, a program files partition and a media partition. Since I really didn't want to install XP from scratch, I cloned this setup on my new drive.

This leaves me one MBR partition entry for installing Windows 7, Ubuntu and ReactOS. I'd like to avoid having to install XP from scratch like the plague, partly because it's supposed to be a safety net in case things go wrong with my other OS's and because I've invested a lot of time getting it set up exactly the way I like it.

Here are the options I've considered and why I don't like them:

  1. Install Windows 7 on my media partition. This would work, but I prefer to keep my media partition completely separate from any OS, so that I can reformat an OS partition without affecting my media partition at all.
  2. Use wubi or something to install Ubuntu in the same partition as something else. Again, this is brittle.
  3. Move all my media to a logical drive on an extended partition. Create another logical drive on this extended partition for Ubuntu. The problem here is that extended partitions are rather brittle--if you nuke one, it renders the rest useless.
  4. Just put the old drive back in my computer and run XP off it. Use the new one for the other OS's. The problem here is that the old drive is slower and uses extra power, generates extra heat, etc.

Can anyone suggest any other possibilities that I may have overlooked?

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2 Answers

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Windows XP requires a primary partition to boot from. I'm not sure about Win-7. Linux does not require a primary partition to boot from (but I consider it a good practice). I'm not sure about ReactOS.

MBR partition tables mean you only get 4 primary partitions. An extended partition counts as a primary for this purpose, so what you want is 3 primary and 1 extended. The extended partition is where you can create as many logical partitions as you want/need.

Let's look at the options you've considered.

  1. Poor choice. Your preference is a good partition scheme in my book; see below.
  2. Poor choice. As you say, brittle. Wubi's more for letting you try linux without getting messy.
  3. Yes. No, extended partitions are not brittle -- they are very stable, unless you really break the extended partition table. Linux partitioning tools like fdisk and parted have no trouble deleting and recreating logical partitions inside an extended partition.
  4. Poor choice.

What you really need to do is decide on a partition scheme now, before you go any further. If I were you, I'd back up the media partition to another drive and plan a complete (or nearly complete) repartitioning. If your WinXP partition is already the first primary partition, and is fairly small, you can probably leave it alone while you repartition the rest of the drive.

See my answer on "How to prepare a flexible partition scheme?" for my general recommendations.

For your specific case, consider this partitioning scheme. Spaces shown are only examples, but notice how most of the space is at the end, in the media partition, and any free space is in the extended partition where it can be used to create new logical partitions at any time.

  • Primary 1 (WinXP) (40gb)
  • Primary 2 (Win7) (40gb)
  • Primary 3 (Linux or /boot) (/boot can be small) (4gb)
  • Primary 4 (extended partition)
    • Logical 1 (Linux) (40gb)
    • Logical 2 (ReactOS?) (40gb)
    • Logical 3 (Linux swap) (4gb)
    • ... (free space?) (1000 - 600+170 = 230gb)
    • Logical N (Media storage partition) (600gb) (place at the very end of the drive)

Setting a new partition scheme when you've already got data on the drive can be a pain, but if your partition scheme isn't set correctly you'll just end up with more trouble down the road. Take the time to get it right before you fill up the drive even more.

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I think that the partition scheme suggestion of quack quixote is a good point. I also suggest you to take a look at LVM (Logical Volume Manager): that primarily because, as quack states, "setting a new partition scheme when you've already got data on the drive can be a pain", but it seems that you really enjoy testing...so your partition table could be more flexible with [LVM][1] than with the static setting method. [1]: tldp.org/HOWTO/LVM-HOWTO –  dag729 Apr 24 '10 at 12:34
@dag: LVM has nothing to do with the partition table. LVM provides linux systems with a "logical volume" that acts a bit like logical partitions. but LVM must be given a real partition (primary or logical) to carve its "logical volumes" out of. LVM is not windows-accessible. –  quack quixote Apr 24 '10 at 12:38
LVM could be used to provide a sizeable chunk of Linux storage, say on the "Logical 1" node above. if that were given to LVM to manage, and "Primary 3" kept as /boot, then with LVM one could configure several small (~8GB) Linux installations in the same logical partition. LVM would only be applicable to the linux installations, however. –  quack quixote Apr 24 '10 at 12:40
Yet you could do two primary partitions for Win XP and Win 7, the third partition a /boot (primary as well), then an LVM for every *NIX-like, and a logical partition for storage (FAT32 or NTFS): couldn't you? –  dag729 Apr 24 '10 at 23:03
@dag: yes, that's what i said. you couldn't use LVM for every Unix-like; just the ones that understand LVM. (i'm not sure if anything other than Linux does.) –  quack quixote Apr 25 '10 at 5:25
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You could get another hard drive, just to install the OS on so it wouldn't need to be large.

You could also merge your program files + media partition, and then you'd have 2 free partitions for Linux and Windows 7.

Or you can merge your program files with your XP.

Depending on how often you boot to the other OSs you could drop them all into one partition, but into their own logical partitions, except for the one you like the most, so in case anything breaks in the logical partition you can still use the computer.

If you changed the format of your hard drive you could swap to one that can support more partitions. However, I'm not sure if you'll still be able to boot from it etc... but if you can then it is a possibility.

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