HOWTO/man: Describe trim support by zone reset for zoned devices

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 86fb296445f006e2f3416abe559bd5f0dc57ce19..04ea284b5badc3cde2c31a7987fb2ea32918afcb 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -992,6 +992,9 @@ Target file/device
                                single zone. The :option:`zoneskip` parameter
                                is ignored. :option:`zonerange` and
                                :option:`zonesize` must be identical.
+                               Trim is handled using a zone reset operation.
+                               Trim only considers non-empty sequential write
+                               required and sequential write preferred zones.
 
 .. option:: zonerange=int
 
@@ -1055,6 +1058,11 @@ Target file/device
        number of open zones is defined as the number of zones to which write
        commands are issued.
 
+.. option:: job_max_open_zones=int
+
+       Limit on the number of simultaneously opened zones per single
+       thread/process.
+
 .. option:: zone_reset_threshold=float
 
        A number between zero and one that indicates the ratio of logical
@@ -1705,6 +1713,36 @@ Buffers and memory
        this option will also enable :option:`refill_buffers` to prevent every buffer
        being identical.
 
+.. option:: dedupe_mode=str
+
+       If ``dedupe_percentage=<int>`` is given, then this option controls how fio
+       generates the dedupe buffers.
+
+               **repeat**
+                       Generate dedupe buffers by repeating previous writes
+               **working_set**
+                       Generate dedupe buffers from working set
+
+       ``repeat`` is the default option for fio. Dedupe buffers are generated
+       by repeating previous unique write.
+
+       ``working_set`` is a more realistic workload.
+       With ``working_set``, ``dedupe_working_set_percentage=<int>`` should be provided.
+       Given that, fio will use the initial unique write buffers as its working set.
+       Upon deciding to dedupe, fio will randomly choose a buffer from the working set.
+       Note that by using ``working_set`` the dedupe percentage will converge
+       to the desired over time while ``repeat`` maintains the desired percentage
+       throughout the job.
+
+.. option:: dedupe_working_set_percentage=int
+
+       If ``dedupe_mode=<str>`` is set to ``working_set``, then this controls
+       the percentage of size of the file or device used as the buffers
+       fio will choose to generate the dedupe buffers from
+
+       Note that size needs to be explicitly provided and only 1 file per
+       job is supported
+
 .. option:: invalidate=bool
 
        Invalidate the buffer/page cache parts of the files to be used prior to
@@ -1930,6 +1968,11 @@ I/O engine
                        character devices. This engine supports trim operations.
                        The sg engine includes engine specific options.
 
+               **libzbc**
+                       Read, write, trim and ZBC/ZAC operations to a zoned
+                       block device using libzbc library. The target can be
+                       either an SG character device or a block device file.
+
                **null**
                        Doesn't transfer any data, just pretends to.  This is mainly used to
                        exercise fio itself and for debugging/testing purposes.
@@ -2109,6 +2152,9 @@ I/O engine
                        achieving higher concurrency and thus throughput than is possible
                        via kernel NFS.
 
+               **exec**
+                       Execute 3rd party tools. Could be used to perform monitoring during jobs runtime.
+
 I/O engine specific parameters
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -2536,6 +2582,28 @@ with the caveat that when used on the command line, they must come after the
        URL in libnfs format, eg nfs://<server|ipv4|ipv6>/path[?arg=val[&arg=val]*]
        Refer to the libnfs README for more details.
 
+.. option:: program=str : [exec]
+
+       Specify the program to execute.
+
+.. option:: arguments=str : [exec]
+
+       Specify arguments to pass to program.
+       Some special variables can be expanded to pass fio's job details to the program.
+
+       **%r**
+               Replaced by the duration of the job in seconds.
+       **%n**
+               Replaced by the name of the job.
+
+.. option:: grace_time=int : [exec]
+
+       Specify the time between the SIGTERM and SIGKILL signals. Default is 1 second.
+
+.. option:: std_redirect=boot : [exec]
+
+       If set, stdout and stderr streams are redirected to files named from the job name. Default is true.
+
 I/O depth
 ~~~~~~~~~