doc: add ftruncate engine documentation and example jobfile

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 80b9e75a75cf52ba86b38f6e1addea8f4a118b52..ffdcb755f1a25a0f41158ae2767826a3ec910ac8 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -1675,6 +1675,11 @@ I/O engine
                        DDIR_TRIM
                                does fallocate(,mode = FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE).
 
+               **ftruncate**
+                       I/O engine that sends :manpage:`ftruncate(2)` operations in response
+                       to write (DDIR_WRITE) events. Each ftruncate issued sets the file's
+                       size to the current block offset. Block size is ignored.
+
                **e4defrag**
                        I/O engine that does regular EXT4_IOC_MOVE_EXT ioctls to simulate
                        defragment activity in request to DDIR_WRITE event.