Dual Boot - Partition Help - Bios

Hello,
I looked up for similar topics, even found one similar (Dual Boot Partitioning Help), but the disclosure didn't helped me.
I trying to dual boot windows 10 and Manjaro.

INFO:

  • Acer Aspire V3-571G
  • Inter Core i7-3632QM 2.2Ghz
  • 6 GB DDR3
  • 500 GB HDD
  • Nvidia GeForce GT 640M
  • Came with windows 8 updated to Windows 8.1 then to Windows 10
  • Boot mode: Legacy BIOS
  • Secure Boot: Disabled

QUESTION:
Don't know why, but the BIOS only allows 4 primary partitions. As you can see from the image, I have:

  1. Windows C: - 243.03 GB
  2. My backup E: - 221.62 GB
  3. System reserved - 350 MB (I guess this belong to windows)
  4. Recuperation partition - 782 MB ( I don't know what is this, maybe from windows too)

linux%20gerencia%20disco%20(2)

My plan was to take 40~50 GB from C: partition and make the Manjaro installation. I actually got it shrinked, but when I was going to turn it into some other partition (F: for example), got a message denying it. How I suppose to manage this?
As many people say ( and my badge too) I'm a newbie to Linux. trying to slowly get away from windows, and start to understand more about how the system works. Really appreciate for you time.

This is why. If your disk has an legacy/mbr table on it, you are limited to 4 primary partitions. You will need to delete one of the partitions and replace it with an extended partition. You can then put more partitions in that.

If you disk has a gpt partition table on it, you can have more than 4 partitions.

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Yes, nowadays, machines that come pre-installed with Microsoft Windows always have a recovery partition, from which you can re-install the pre-installed version of Windows. This is because they are no longer shipping an installation DVD with the computer.

Either way, as @dalto says, you cannot have more than 4 primary partitions in a DOS MBR partition table. So if you want to stick with that partition table, then you must replace one of the primary partitions with an extended partition container, and then this extended partition container can in turn contain logical partitions.

The better approach however would be to use a GUID partition table, also known as GPT. It is more robust than the DOS MBR partition table, and it can be used whether the machine boots in UEFI mode or in legacy BIOS mode. There are however differences between both boot methods if you're going to go with a GPT.

  • In the event of a GPT in combination with UEFI boot, you'll need a special EFI System Partition (ESP) of about 512 MiB, formatted with FAT32. This partition is used for storing the so-called efivars ─ i.e. the entries for the native UEFI boot manager. The ESP must be marked with the "bootable" and "esp" flags.

  • In the event of a GPT in combinaton with legacy BIOS boot, you'll need a special partition of type "BIOS" of approximately 5 MiB ─ marked with the "bootable" flag ─ but without a filesystem on it, and this partition must be the first one you create.

In both cases, the partition boundaries must be aligned to the (binary) megabyte.

Another thing that's also imperative is that you cannot use two operating systems on the same HDD when one of them is set to boot in UEFI mode and the other is set to boot in legacy BIOS mode, because in that case, the firmware will always boot the legacy BIOS installation.

So you must either install both operating systems in UEFI mode (and with Secure Boot disabled), or you must install them both in legacy BIOS mode.


P.S. 1: GNU/Linux does not use drive letters, because it is a UNIX system, and UNIX approaches disk storage in a different manner. Drive letters are specific to Microsoft Windows, and were inherited from the original CP/M system by way of DOS, and then later, OS/2.


P.S. 2: You'll need at least two partitions for GNU/Linux itself, one being a root filesystem (/) and a dedicated swap partition. Recommended is to have three partitions, being a root filesystem (/), a separate partition for /home (where your user-owned configuration files and data will live) and a swap partition.

In your case, given that you have 6 GiB of RAM, the swap partition should be about 8 to 10 GiB. You can get by with less, but not if you plan to hibernate the machine ─ i.e. suspend-to-disk.

Your root filesystem should be at least 50 GiB ─ not that you will be using up all of that after a clean install, but as time passes and you periodically install system updates, the downloaded packages will be stored on-disk by default, and then that quickly runs up to quite an amount of space. You must never allow the root filesystem to fill up, because then you'll be in bigger trouble. :wink:

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First, Thank you all for such a quick answers!

@dalto, that's what I thought my problem was. Thanks to confirm it. As a complement question, I was going to ask, what could happen if I delete the Recuperation Partition. But @Aragorn was much quicker, and thanks for the class you gave me.

What if I transfer my things in backup partition in an external HD and turn the E: partition into my Manjaro partition, could this be an easier, and safer, way to deal with it?
Another question, reading the "Manjaro User Guide" ( and @Aragorn said it too) I found that to install a Linux I need two more partitions (format ext4) and one for swap. those partitions count as primary partitions to the BIOS?

Well, that depends on how you create them. If you create an extended partition container, then you can start creating logical partitions in it. If on the other hand you create a primary partition, then you're back to the same problem.

I would recommend using gparted for creating/managing the partitions before you install anything. It gives you more options. :wink:

Yes, but make it an extended partition and put your Linux partition inside it. Then you have a dedicated swap partition if you want one.

That being said, you don't really need a dedicated swap partition. The real world performance difference between a swap partition and a swap file is minimal.

It's not just a matter of performance, compadre. It's also about robustness. With a swap file, the kernel needs to pass through the filesystem layer in order to access the raw disk blocks, and that puts another possible point of corruption on its path.

In addition to that, it also imposes restrictions on the type of filesystem one can use, because then the filesystem cannot be allowed to pull some performance-enhancing tricks. For instance, if you put a swap file on btrfs, then you must disable the copy-on-write and the compression. This is of course not a problem with ext4, but it is something to keep into account.

Got it!
there are two ways to deal with it.

  1. Turn my Backup Partition into the Linux Partition (with gparted :wink: @Aragorn) and install Manjaro in it.

or

  1. Turn the DOS MBR partition table into GUID partition table. Than I can have up to 8 primary partitions.

Is that right?
Guess I'll be moving my files to an external HD, and use this time to learn more about the second option. Sounds more challenging, but looks like an opportunity to know more about it.

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GPT allows for 128 primary partitions. :wink:

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Well, I got the "8" right. :laughing:

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Thank you so much guys, for real. It was great to learn from you, in such a small time. I'm going to study a little more and make this right.
Closing this Topic!

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I think it allows for much more than 128 partitions. Nothing mentioned in the link.

Msdos disks allow for at least 126 partitions, including logical partitions, I think.

A reliable link on number of partitions in gpt and msdos would be good. Whatever, either gpt or msdos, it will be more than sufficient.

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It mentions 128 physical partitions and ─ quote ─ "hundreds of virtual partitions" in combination with volume management. :white_flag: :slight_smile:

So essentially we get the following...

PARTITION TABLE FORMAT               NUMBER OF PHYSICAL PARTITIONS

MBR - primary partitions only            4
MBR - primary + logical partitions     127 + 1 extended partition container
GPT                                    128

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Thanks for the link. But I prefer a more authoritative reference than a user post. I had read long ago that msdos can have 126 partitions and gpt at least 360 (there were references elsewhere for much more than that); but I couldn't find the links anymore. There was a topic between wongs and I on the subject here some time back. I had a msdos disk with about 17 or 18 partitions (15 OS's). Don't have it anymore.

Oh re you latest edit... in a reply...

Who told you that the EFI partition table contains up to 128 partitions? That person cannot read specifications. As I've said before, 128 entries of 128 bytes each is the minimum size that is required by the EFI Specification, not the size of an EFI partition table, and certainly not the maximum size.

I think that reply is accurate. But I would still want an authoritative link, if possible. Thanks.

Cheers.

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This is interesting.

How many partitions can a GPT disk have?
The specification allows an almost unlimited number of partitions. However, the Windows implementation restricts this to 128 partitions. The number of partitions is limited by the amount of space reserved for partition entries in the GPT.

https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-and-gpt-faq#how-many-partitions-can-a-gpt-disk-have

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