After this post I tried to follow the procedure detailed in this post in order to have more space to install software in easy debian.

1) I created a new partition in the sd card
2) I mounted the current Debian image with the command 3) I mounted the new formatted partition
4) I copied the content of /debian to the partition
And here is where my problems started. The commands provided in the previous post are:
Unfortunately I got errors (not able to access) the directory /home/user/img-install/

I thus run only the command However I have some questions:
Is it using /home/user/img-install/ because it is the directory where the image was installed?
Are there (in /home/user/img-install/) files needed in the partition?

5) restart device: I did so and the device was almost bricked. I had to remove the sd card before being able to restart the N900.

I reinserted the sd and

6) Edit the /home/user/.chroot
changing the IMGFILE to the partition where the files are

And easy debian started with 2 more gb free!

However I am just wondering if the changes I made in step 4 make sense or if they can lead to a problem.

I did not try to restart the N900 for the moment, but do you think that having three partitions (1 small fat, 2 ext2) on the sd may be a problem?

Thank you very much in advance!

P.S. If you agree and if what I did is kind of correct I can enter the procedure in the wiki in the next days.