Ubuntu for Windows Users: Where Do I Install Ubuntu? How Much Disk Space Do I Need?

Screenshot of graphical Disk Usage Analyzer

Where to install Ubuntu (or any other operating system, for that matter) and how much disk space will be needed is a tricky proposition at best.  In fact, this can be the biggest problem in doing the setup, as one single mistake can really ruin your day.  Therefore, the very first question to answer should be: Where am I going to back everything up?  You really need a disk image handy in any event, but when making major changes like where disk partitions reside, it becomes a much bigger deal.

Next, where will your data reside?  Hopefully, you’ve already decided “Where Is Home?”  If you are not using the same area for data as your Windows operating system, then at least consider putting your entire home directory on a different partition.  This segregates the data so that if anything happens to the operating system, there is less of a chance of affecting the data.  Remember, an OS is a lot easier to get back than data.  Again, though, this is not foolproof and frequent backups are always required.

Next is the question of how much disk usage you will need.  If you are sharing data with your Windows system, then hopefully you already have that covered. I cannot tell you how much you will need, as it will depend upon a lot of factors.  If you have a lot of documents but only a few photos and music files, then you will not need much.  If you have a lot of videos, however, you will need a lot.  If you have photos, videos and music files, then you’re better off getting a 1TB drive and allotting at least half of it to data.

One way you can use to estimate how much you’ll need is to determine how much you are using right now and extrapolate out.  If you have already filled your 250GB drive with photos, but it took you 5 years to do so, then it isn’t unreasonable to expect it would take you 5 years to fill another 250GB.  Having said that, if your computer if 5 years old, do you reasonably expect it to last another 5 years?  Now you can see why it can be confusing and difficult to predict.  Also, some of that 250GB are probably downloads you no longer need, operating system and program files.  You can use a tool like WinDirStat in Windows to narrow it down to just data, and the link to WinDirStat also has suggestions for Linux and Mac OS X.

After narrowing down the amount needed for data, you can turn your attention to how much you will need for programs and Ubuntu itself.  You may be surprised at how little you will actually need.  I have mine on a 70GB partition, but I’m actually using less than 10GB for the programs.  As you can see from my screenshot above, I’m using almost twice that just for Windows alone.  IMO, unless you have specific concerns (say, a special program that will be used that was not used under Windows), I believe you could get by creating a root partition (‘/’) of the size of the sum of your Windows, Progam Files and Program Data folders.  That actually is probably much, much more than you will initially need, but you don’t want to accidently restrict yourself to the point where you cannot expand due to unforeseen needs and/or do future Ubuntu upgrades because you have no disk space left.

Finally, there is the always much debated amount needed for swap.  Windows uses a portion of the drive to create a swap file, but Linux places its swap data into a completey separate partition.  How much is needed?  Well, just like suggestions for Windows swap, you can get different opinions on the topic.  In general, a swap partition is normally as large as the amount of RAM you have.  However, and this is not clear for version 13.04, there are indications that Ubuntu also uses the swap partition for hibernation.  If you are using a desktop, this might not be of concern, but most laptop users will want to turn on hibernation if possible.  Since hibernation dumps all memory to a file, then the swap partition must be as large as RAM to enable it.

So, here is the question for which the answer is not clear: If you have a laptop and want to use hibernation, should the swap partition then be twice that of RAM?  I don’t know, but it seems prudent to me to set it up that way and not need it rather than trying to resize partitions later.  If I find out this is in error, I will edit and/or comment on this post to correct it.

The only other thing to keep in mind is that a disk drive can contain only so many primary partitions.  Unfortunately, once an extended partition with logical drives is created, it is very difficult to move it.  You can move within the extended partition, but actually resizing the extended partition itself is a real pain.  You can read up on primary and extended partitions on Super User and Wikipedia.  Where this matters most is on systems with a manufacturer’s utility and/or recovery partition, as these are normally primary partitions for special use.  Even though they are special use partitions only occasionally used, they will use up one of the four allowed partitions if they are primary partitions, which will likely force Ubuntu into an extended partition.

Prior planning is essential to avoid headaches later.  If this seems over your head or too difficult, keep in mind:

  • Having a valid disk snapshot using a reliable tool like Clonezilla or Acronis True Image Home can relieve your anxiety somewhat, as you can undo any mishap within a couple of hours.  Be sure they are verified images, however.  Your recovery will be only as good as your backup, after all.  The latest Clonezilla has a nice feature where it will offer to verify the image once the backup has been completed.  Acronis has a tool that can verify an image in the full install version.  It should be noted that Acronis requires Windows for the full install, although it can be booted from CD with a more limited set of features.
  • The Ubuntu install will help to lead you through the process as much as practical.  However, it will not do the planning for you.
  • If you’ve already tried out previous versions of Ubuntu, there are other considerations.  For example, an Ubuntu upgrade always leaves behind the previous kernel, just in case of emergency.  It is up to you to do the cleanup on any prior kernels.  In addition, you must upgrade from release to release, and you cannot skip over any major release.  This means that if you have 12.04, you must install 12.10 before you install 13.04, and now you will have two older kernels taking up a little bit of disk space.  In the end, when upgrading you will probably be best off using the partitions you set up the first time, perhaps resizing them beforehand.  You can still map data folders if you wish, however.

Again, I believe figuring out how much disk space is needed and where to place it all is actually the most difficult step for most people.  The second-most difficult is actually learning to use a different operating system.  However, in both areas, Ubuntu has taken Linux a long way from the days of having to compile your own kernel to ensure you have the correct drivers.  In addition, the install does a decent job of guiding you along the way.  There still are some questions that you must answer, though, no matter how much help an operating system install provides.