Creating a large file, shoud not stop any other operation

[tgrall]

In the current implementation if you do the following:

1- In one Terminal, in the source folder run the following command:

dd if=/dev/zero of=256m.img bs=1 count=0 seek=256M

2- In the same time, in another terminal create a new small file, or other command

echo 'ccccc' > foo.txt

Today the first operation blocks the 2nd, we should find a way to avoid blocking operations