To share data in a multi boot scenario a user may use a separate partition for data, for example having a Windows partition, a Linux partition and a data partition storing documents, pictures, music, video and other user files. A user may wish to avoid data duplication by storing their Dropbox folder on the data partition, rather than having separate copies for each operating system. This guide covers how this can be achieved in a Windows/Linux dual boot scenario however the ideas described are applicable to more general multi boot scenarios.

An additional benefit of this set up is that if either of the operating systems or operating system partitions becomes unusable the data is still accessible from the other operating system or from a live cd.

Overall plan

  1. Create a separate partition for data that can be accessed by both Windows and Linux.
  2. Store Dropbox folder on data partition.
  3. Set up Dropbox to use the Dropbox folder on the data partition.

1. Creating the data partition

This can be done when installing new operating systems onto a computer or after operating systems have been installed. How to create the partition is outside the scope of this guide however useful tools include:

  • Gparted, the official GNOME Partition editor. This can be used for creating, deleting and resizing partitions. It’s included on SystemRescueCD, a repair and maintenance live cd.
  • Windows Disc Management, part of Windows. This can be used for creating, deleting and resizing partitions. In Windows Vista and above it can also be used to shrink partitions.

The data partition needs to use a file system that is accessible from both Windows and Linux which gives a choice between NTFS and FAT. NTFS is now well supported in Linux and is a much superior file system to FAT.

This guide assumes that the data partition has been created and appears as drive D: in Windows and is mounted at /media/data in Linux.

Warning : These partition tools are good but not flawless, be cautious and back up before manipulating partitions.

2. Storing Dropbox folder on the data partition

The choice of where on the data partition to store the Dropbox folder is pretty much arbitrary, one possible set up for the data partition is described below:


3. Set up Dropbox to use the Dropbox folder on the data partition

There are several different methods to set Dropbox up to use the Dropbox folder on the data partition.

Method A

This is definitely the simplest method, change the Dropbox folder location in the Dropbox preferences. This is a now a possible solution as the Dropbox folder has the same name under Windows as Linux, ‘Dropbox’.

The only catch here is that you specify the folder where the Dropbox folder resides, rather than the Dropbox folder itself.

Method B

Some users may wish to have the Dropbox folder appear on their desktop, for example so that they drag files into it and find the folder more quickly in dialogues. This can be achieved by linking a folder on the users desktop to their Dropbox folder on their data partition. Dropbox will interact with the Dropbox folder on the desktop which will appear to contain the Dropbox data but is actually just a link to the real Dropbox folder where the data is stored. From the Dropboxs point of view this is transparent.

The order in which this method is carried out is important in order to stop Dropbox overwriting the link.

  1. On either Windows or Linux make a copy of Dropbox folder onto the data partition. For example for Windows copying the data in ‘C:\Users\Calum\Dropbox’ to ‘D:\’AppData\Dropbox’.
  2. Keeping on that operating system alter Dropbox preferences so to use a folder on the desktop as the Dropbox folder. For example ‘C:\Users\Calum\Desktop\Dropbox’, bearing in mind to specify the folder to hold the Dropbox folder, not the Dropbox folder location itself.
  3. Quit Dropbox.
  4. Delete the Dropbox folder that has been created on the desktop.
  5. Link a folder on the desktop of the same name as the folder just deleted to the Dropbox folder on the data partition. How to do this is explained in the next three sections.
  6. Restart Dropbox to check things are working correctly. It should not create an additional folder on the desktop or ask to relink.
  7. Now repeat steps 2 to 6 for the other operating system.

Creating a symbolic link in Linux 

In Linux this can be achieved using a symbolic link which creates a file or directory which points to the location of another file or directory. The ‘ln’ command creates the link and the ‘-s’ flag specifies the creation of a soft rather than hard link.

 $ ln -s /media/data/AppData/Dropbox /home/calum/Desktop/Dropbox

The difference here is how exactly the link is created within the filesystem. The negative affect of creating a hard link is that space usage of the desktop Dropbox folder would be size of the Dropbox folder on the data partition when it actually only takes up a very small amount of space. This happens because the software is unaware there folder is linking to another folder however with a soft link software is aware but can interact with the folder as if the data really was in the Dropbox folder on the desktop.

Creating a symbolic link in Windows 7

Windows 7 also has support for symbolic links which can be created using the ‘mklink’ command. The ‘/D’ flag specifies the creation of a directory rather than a file symbolic link.

 $ mklink /D C:\Users\Calum\Desktop\Dropbox D:\AppData\Dropbox

Creating a junction in Windows 2000/XP/Vista

Prior to Windows 7 there is no support in Windows for symbolic links however there is for a related concept, junction points. These are closer to hard links as Windows reports the disc usage of the function as that of the folder it points to.

This can be achieved using the Junction utility from SysInternals or fsutil in Windows XP.

 $ junction "D:\AppData\Dropbox" "C:\Documents and Settings\Calum\Desktop\Dropbox"
 $ fsutil hardlink create "D:\AppData\Dropbox" "C:\Documents and Settings\Calum\Desktop\Dropbox"

Useful links