iolog: fix disk stats issue

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index f151350ce39b221246316848c4648b80b7a9b1c0..dce96bcd8103f075d56b21173659f3061f6600b1 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1453,8 +1453,8 @@ Buffers and memory
        mix of random data and a fixed pattern. The fixed pattern is either zeros,
        or the pattern specified by :option:`buffer_pattern`. If the pattern option
        is used, it might skew the compression ratio slightly. Note that this is per
        mix of random data and a fixed pattern. The fixed pattern is either zeros,
        or the pattern specified by :option:`buffer_pattern`. If the pattern option
        is used, it might skew the compression ratio slightly. Note that this is per

-       block size unit, for file/disk wide compression level that matches this
-       setting, you'll also want to set :option:`refill_buffers`.
+       block size unit, see :option:`buffer_compress_chunk` for setting a finer
+       granularity of compression regions.

 
 .. option:: buffer_compress_chunk=int
 
 
 .. option:: buffer_compress_chunk=int
 


@@ -1463,7 +1463,8 @@ Buffers and memory
        will provide :option:`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
        will provide :option:`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

-       I/O buffer.
+       I/O buffer. This is particularly useful when bigger block sizes are used
+       for a job. Defaults to 512.

 
 .. option:: buffer_pattern=str
 
 
 .. option:: buffer_pattern=str
 


@@ -1819,6 +1820,11 @@ I/O engine
                        set  `filesize` so that all the accounting still occurs, but no
                        actual I/O will be done other than creating the file.
 
                        set  `filesize` so that all the accounting still occurs, but no
                        actual I/O will be done other than creating the file.
 

+               **libpmem**
+                       Read and write using mmap I/O to a file on a filesystem
+                       mounted with DAX on a persistent memory device through the NVML
+                       libpmem library.
+

 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~