I am writing an embedded application based on ARM 9 v5 processor, and using NAND of size 64 MB. My problem is that when I copied the text or binary files of sized 3-4 MB the free physical memory gets reduced by only few KB's, whereas ls -l show the file size in MB. By repeating same process i reached one point where df command shows me 10 MB size is free and du show the total size 239MB. how this can be happen as i have only 64MB of NAND how i am able to add files upto 239 MB of size. please reply. i need help to solve this problem. Thank in advanced.