fio: add libpmem engine

[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
-       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
 
@@ -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
-       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
 
@@ -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.
 
+               **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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~