Quote Originally Posted by Frunktz
When a program is executed, a part of that is decompressed..in the ram? And if the ram isn't enought?
Yea, it decompresses the program and runs it in RAM. If you don't have enough RAM and you have a swap file or swap partition it can use that as virtual memory, otherwise it likely can't run (it could keep swapping in parts of the code on from the CD, since the code doesn't change during the run, but as far as I know that doesn't happen).

Quote Originally Posted by Frunktz
Other question, if the image is decompressed on the fly when requested, why "df -h" show 1.9 GB on /dev/cloop?
Magic. Either that or 'cause that is how big the file system thinks it is, since it's being fooled by the cloop code; either answer is as good as the other.