I think 'gzip -l' is having trouble reporting statistics on files whose uncompressed size is > 4Gbytes. Has anyone else seen this problem? Do I contact Gnu about this? Cheers, Terry. alf1_tsh> gzip -l /scr0/boris/*.gz compressed uncompr. ratio uncompressed_name 2556072487 596983808 -328.1% /scr0/boris/Anopheles_gambiae_FASTAruns.tar 1159485670 4174428160 72.2% /scr0/boris/Apis_mellifera_FASTAruns.tar 2510639403 550125568 -356.3% /scr0/boris/Caenorhabditis_elegans_FASTAruns.tar 2128120566 3518132224 39.5% /scr0/boris/Drosophila_ananassae_FASTAruns.tar 2618523155 506277888 -417.2% /scr0/boris/Drosophila_melanogaster_FASTAruns.tar 2138507079 3865974784 44.6% /scr0/boris/Drosophila_mojavensis_FASTAruns.tar 1699621242 1498527744 -13.4% /scr0/boris/Drosophila_pseudoobscura_FASTAruns.tar 1592022108 1111363584 -43.2% /scr0/boris/Drosophila_simulans_FASTAruns.tar 2059666954 3298607104 37.5% /scr0/boris/Drosophila_virilis_FASTAruns.tar 2363369933 76412928 -2992.9% /scr0/boris/Drosophila_yakuba_FASTAruns.tar 20826028597 19196833792 - 8.4% (totals) e.g. if I gunzip /scr0/boris/Drosophila_yakuba_FASTAruns.tar, I get an 8Gbyte uncompressed file. and I suspect all the negative ratios ars for files which would have uncompressed to > 4Gbytes.