After deleting data from the history (by clicking the little X in the corner), it is not fully deleted from the system. In order to permanently remove it, you can go into the history options (the little wheel in the top right) and select 'include deleted datasets' to see the items you have deleted, and click 'permanently remove from disk' to delete them individually. Alternately, if you're sure you want to erase all the files you have deleted, you can select 'purge deleted datasets' from the history options drop down menu.
Hope this helps
Thank you for your answer,
I have already done everything you are saying but nothing worked, I still have lots of memory occupied and that means I have to stop making analysis given that I got an error for the insufficient space.
Can you please solve this problem?
Thank you very much again,
In addition to checking datasets within the active history, be sure to check all histories. You will be most likely looking for histories that are deleted, but not permanently deleted. Details are on this wiki: http://wiki.galaxyproject.org/Learn/ManagingDatasets
If you are still having problems after going through the process, send an email to galaxy-bugs@bx,psu.edu with your account's email address and a link to this post for us to examine.
Thanks! Jen, Galaxy team
I have solved the problem sending an email to galaxy-bugs@bx,psu.edu, this is their answer:
"In your account, under histories, go to "Saved Histories", select "Advanced Search", and look at your deleted histories".
I did this and I effectively saw there were some undeleted permanently files.
Thanks a lot