I've prepared a PC for installing Ubuntu 12.04 LTS alongside Windows Vista. These are the steps I've taken:

  1. Shrunk the C: drive to create 60GB for Ubuntu. The Disk Management utility confirms that part of the disk is unallocated.
  2. I put Ubuntu on a USB stick using the USB installer provided at pendrivelinux.com.
  3. I then booted my PC from the USB stick and the installation process began.
  4. At the welcome screen I selected "Install Ubuntu"
  5. At the Preparing to Install Ubuntu screen all the conditions were satisfied.
  6. At the installation type I selected the option to install Ubuntu alongside them.

Then the message pops up:

Unable to satisfy all constraints on the partition.

Can anyone explain how to overcome this?

  • 1.Boot Ubuntu installation disk,2.select Try Ubuntu 3.Ope Gparted from Dash.4.Take a screenshot 5.Upload it to imgur.com and provide the link here.I think there might be an option to install Ubuntu on your pc. Jan 18, 2014 at 1:59
  • Hi, I've uploaded to images imgur.com/Ja0buQ5 and imgur.com/PbiGm6q
    – ksl
    Jan 18, 2014 at 10:56
  • what was your /dev/sda?or it has only two options sdb and sdc? Jan 18, 2014 at 11:06
  • They were the only two options as far as I know.
    – ksl
    Jan 18, 2014 at 15:14

5 Answers 5


Ubfan1 may be correct; however, you can sometimes use my FixParts program to convert an existing partition from primary to logical without the backup-delete-repartition-restore dance. Be aware that you must not convert some partitions from primary to logical. Windows boot partitions are particularly risky for this type of operation.

Another possibility entirely is that you're running into rounding problems in the partitioning software. The libparted library (upon which Ubuntu's installer, GParted, parted, and various other tools rely) will try to round the start and end points of partitions to 1MiB boundaries by default. If existing partitions are not aligned in this way, libparted may try adjusting the specified start point, thus moving it into an overlap with an existing partition. The program then responds with an "unable to satisfy all constraints" message. The solution in this case is to create your partitions with small gaps between the new partition(s) and existing ones. A 1MiB gap should be sufficient, but it's conceivable you'll need a 2MiB gap. Creating partitions with another tool, such as fdisk or gdisk, may help, too. Be aware of the reasons for 1MiB alignment, though. I wrote this article on the subject some time ago. (An update is in the works, but hasn't yet been published.)

  • I've uploaded two images as requested by Avinash Raj. mgur.com/Ja0buQ5 and imgur.com/PbiGm6q. Can you tell from either if your theory regarding the rounding problems applies?
    – ksl
    Jan 18, 2014 at 10:59
  • You've got just two partitions, so you're not running into the 4-partition limit. This makes it more likely that you're running into the rounding-error issue I suggested, but I can't confirm that hypothesis based on those screen shots. Try the recommended solution and see if it works.
    – Rod Smith
    Jan 18, 2014 at 14:40

You may have at most four primary partitions. You are probably maxed out, so cannot create any more. Minimum, you will need to create a root (/) partition and a swap partition. You need to make a primary partition an extended partition, and then make logical partitions inside that (Ubuntu doesn't care if its partitions are primary or logical). If you only have 3 primaries, then create an extended partition with the free space, and then make the root and swap logical partitions in the extended. use any disk partitioning tool for this. If you have 4 primaries, you need to back up one, delete it, remake the free space into an extended partition, make a logical partition to restore the deleted primary, and then make your root and swap partitions. You can format the root during the installation.

  • The disk only has two allocated partitions - the main one and a recovery one. The rest is unallocated.
    – ksl
    Jan 18, 2014 at 8:14
  • To be more specific: the disk has two primary partitions. The disk management utility indicates the following for the C: drive: System, Boot, Page File, Active, Crash Dump, Primary Partition. It indicates Primary Partition for the D: drive and there is 60GB marked as Unallocated. So am I correct to assume that it is not maxed out as far as primary partitions go?
    – ksl
    Jan 18, 2014 at 10:37

Try to create an ext4 partition on 59 GB unallocated space using Gparted Partition Editor Utility.

Then run the ubuntu installer and choose something else option to install ubuntu on the created ext4 partition.


I'm not clear why the installer is having trouble here, but you could try creating the partitions you need/want manually with gparted, and then selecting those manually during the installation. Even if it doesn't work, gparted may give you a more informative error message.


Solved by adding 1MB before and 1MB after the partition. With Gparted it sounds like thatenter image description here

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