On August 3, 2017 7:01:06 PM GMT+03:00, Goffredo Baroncelli >The file is physically extended > >ghigo@venice:/tmp$ fallocate -l 1000 foo.txt
For clarity let's replace the fallocate above with: $ head -c 1000 </dev/urandom >foo.txt >ghigo@venice:/tmp$ ls -l foo.txt >-rw-r--r-- 1 ghigo ghigo 1000 Aug 3 18:00 foo.txt >ghigo@venice:/tmp$ fallocate -o 500 -l 1000 foo.txt >ghigo@venice:/tmp$ ls -l foo.txt >-rw-r--r-- 1 ghigo ghigo 1500 Aug 3 18:00 foo.txt >ghigo@venice:/tmp$ According to explanation by Austin the foo.txt at this point somehow occupies 2000 bytes of space because I can reflink it and then write another 1000 bytes of data into it without losing 1000 bytes I already have or getting out of drive space. (Or is it only true while there are open file handles?) -- With Best Regards, Marat Khalili -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html