Fio 3.34

[fio.git] / HOWTO.rst

diff --git a/HOWTO.rst b/HOWTO.rst
index a5f8cc2df3c089de01d7eaaed7985927954e7af7..bbd9496eefb37f952e3dea1f76adbd2df54a2e76 100644 (file)
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -686,10 +686,12 @@ Time related parameters
 
 .. option:: runtime=time
 
-       Tell fio to terminate processing after the specified period of time.  It
-       can be quite hard to determine for how long a specified job will run, so
-       this parameter is handy to cap the total runtime to a given time.  When
-       the unit is omitted, the value is interpreted in seconds.
+       Limit runtime. The test will run until it completes the configured I/O
+       workload or until it has run for this specified amount of time, whichever
+       occurs first. It can be quite hard to determine for how long a specified
+       job will run, so this parameter is handy to cap the total runtime to a
+       given time.  When the unit is omitted, the value is interpreted in
+       seconds.
 
 .. option:: time_based
 
@@ -1088,7 +1090,9 @@ Target file/device
        A number between zero and one that indicates the ratio of written bytes
        in the zones with write pointers in the IO range to the size of the IO
        range. When current ratio is above this ratio, zones are reset
-       periodically as :option:`zone_reset_frequency` specifies.
+       periodically as :option:`zone_reset_frequency` specifies. If there are
+       multiple jobs when using this option, the IO range for all write jobs
+       has to be the same.
 
 .. option:: zone_reset_frequency=float
 
@@ -1108,12 +1112,6 @@ I/O type
        OpenBSD and ZFS on Solaris don't support direct I/O.  On Windows the synchronous
        ioengines don't support direct I/O.  Default: false.
 
-.. option:: atomic=bool
-
-       If value is true, attempt to use atomic direct I/O. Atomic writes are
-       guaranteed to be stable once acknowledged by the operating system. Only
-       Linux supports O_ATOMIC right now.
-
 .. option:: buffered=bool
 
        If value is true, use buffered I/O. This is the opposite of the
@@ -2145,11 +2143,6 @@ I/O engine
                        before overwriting. The `trimwrite` mode works well for this
                        constraint.
 
-               **pmemblk**
-                       Read and write using filesystem DAX to a file on a filesystem
-                       mounted with DAX on a persistent memory device through the PMDK
-                       libpmemblk library.
-
                **dev-dax**
                        Read and write using device DAX to a persistent memory device (e.g.,
                        /dev/dax0.0) through the PMDK libpmem library.
@@ -2432,6 +2425,18 @@ with the caveat that when used on the command line, they must come after the
        For direct I/O, requests will only succeed if cache invalidation isn't required,
        file blocks are fully allocated and the disk request could be issued immediately.
 
+.. option:: fdp=bool : [io_uring_cmd]
+
+       Enable Flexible Data Placement mode for write commands.
+
+.. option:: fdp_pli=str : [io_uring_cmd]
+
+       Select which Placement ID Index/Indicies this job is allowed to use for
+       writes. By default, the job will cycle through all available Placement
+        IDs, so use this to isolate these identifiers to specific jobs. If you
+        want fio to use placement identifier only at indices 0, 2 and 5 specify
+        ``fdp_pli=0,2,5``.
+
 .. option:: cpuload=int : [cpuio]
 
        Attempt to use the specified percentage of CPU cycles. This is a mandatory