path: root/HOWTO
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authorJens Axboe <>2021-07-15 09:54:03 -0600
committerJens Axboe <>2021-07-15 09:54:03 -0600
commitae5c7cdd710dfa97705d965dcf001a96504e5f31 (patch)
treeaf6159f11a6d31c1373884b83878e822a4f286b4 /HOWTO
parentaaedde68bfb2d15c3a444df496ba26ac0956445c (diff)
parent0d71aa983a4dce75a088b3a4831d5b217df066fb (diff)
Merge branch 'dedupe_workset' of
* 'dedupe_workset' of dedupe: allow to generate dedupe buffers from working set
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@@ -1705,6 +1705,36 @@ 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