+buffer_compress_percentage=int If this is set, then fio will attempt to
+ provide IO buffer content (on WRITEs) that compress to
+ the specified level. Fio does this by providing a mix of
+ random data and zeroes. Note that this is per block size
+ unit, for file/disk wide compression level that matches
+ this setting, you'll also want to set refill_buffers.
+
+buffer_compress_chunk=int See buffer_compress_percentage. This
+ setting allows fio to manage how big the ranges of random
+ data and zeroed data is. Without this set, fio will
+ provide buffer_compress_percentage of blocksize random
+ data, followed by the remaining zeroed. With this set
+ to some chunk size smaller than the block size, fio can
+ alternate random and zeroed data throughout the IO
+ buffer.
+