Hi, On 26 April 2017 at 21:19, Bryan Gurney <bgurney@xxxxxxxxxxxx> wrote: > > I performed some tests for various non-zero values of > "buffer_compress_percentage", and the resulting data was not dedupable > (which would be consistent with the behavior of "scramble_buffers=1", but > the data pattern seems to suggest that the algorithm used in > scramble_buffers is not being used. Comparing this to when > buffer_compress_percentage is set to zero, the resulting data is almost > incompressible, but exhibits a high frequency of dedupe. This is despite > the intentions of the user's configuration for buffer data content of 0% > compression, and scrambled to avoid dedupe. http://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-buffer-compress-percentage alludes to buffer_compress_percentage=0 actually turning the option off rather than setting a compression ratio of 0%. Here's a link to the code that would normally react to the option: https://github.com/axboe/fio/blob/fio-2.19/io_u.c#L2045 . -- Sitsofe | http://sucs.org/~sits/ -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
