X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=61ebe5e9f7de732403dfd85b59837f01f987ddac;hp=bcc72b5882be95e4804a641f151cde13b214b432;hb=f491a907983c1022ec3c4d3a76d969c286fe441b;hpb=1ad01bd10933858347d4837eaea520efc4e60c2f

diff --git a/HOWTO b/HOWTO
index bcc72b58..61ebe5e9 100644
--- a/HOWTO
+++ b/HOWTO
@@ -435,6 +435,7 @@ unified_rw_reporting=bool	Fio normally reports statistics on a per
 
 randrepeat=bool	For random IO workloads, seed the generator in a predictable
 		way so that results are repeatable across repetitions.
+		Defaults to true.
 
 randseed=int	Seed the random number generators based on this seed value, to
 		be able to control what sequence of output is being generated.
@@ -960,6 +961,8 @@ random_generator=str	Fio supports the following engines for generating
 
 		tausworthe	Strong 2^88 cycle random number generator
 		lfsr		Linear feedback shift register generator
+		tausworthe64	Strong 64-bit 2^258 cycle random number
+				generator
 
 		Tausworthe is a strong random number generator, but it
 		requires tracking on the side if we want to ensure that
@@ -1198,6 +1201,17 @@ create_only=bool	If true, fio will only run the setup phase of the job.
 			that will be done. The actual job contents are not
 			executed.
 
+allow_file_create=bool	If true, fio is permitted to create files as part
+		of its workload. This is the default behavior. If this
+		option is false, then fio will error out if the files it
+		needs to use don't already exist. Default: true.
+
+allow_mounted_write=bool	If this isn't set, fio will abort jobs that
+		are destructive (eg that write) to what appears to be a
+		mounted device or partition. This should help catch creating
+		inadvertently destructive tests, not realizing that the test
+		will destroy data on the mounted file system. Default: false.
+
 pre_read=bool	If this is given, files will be pre-read into memory before
 		starting the given IO operation. This will also clear
 		the 'invalidate' flag, since it is pointless to pre-read
@@ -1267,6 +1281,12 @@ verify=str	If writing to a file, fio can verify the file contents
 				verified for workloads that write data.
 				See also verify_pattern.
 
+			pattern	Verify a strict pattern. Normally fio includes
+				a header with some basic information and
+				checksumming, but if this option is set, only
+				the specific pattern set with 'verify_pattern'
+				is verified.
+
 			null	Only pretend to verify. Useful for testing
 				internals with ioengine=null, not for much
 				else.
@@ -1433,6 +1453,16 @@ replay_redirect=str While replaying I/O patterns using read_iolog the
 		independent fio invocations.  Unfortuantely this also breaks
 		the strict time ordering between multiple device accesses.
 
+replay_align=int	Force alignment of IO offsets and lengths in a trace
+		to this power of 2 value.
+
+replay_scale=int	Scale sector offsets down by this factor when
+		replaying traces.
+
+per_job_logs=bool	If set, this generates bw/clat/iops log with per
+		file private filenames. If not set, jobs with identical names
+		will share the log filename. Default: true.
+
 write_bw_log=str If given, write a bandwidth log of the jobs in this job
 		file. Can be used to store data of the bandwidth of the
 		jobs in their lifetime. The included fio_generate_plots
@@ -1440,7 +1470,8 @@ write_bw_log=str If given, write a bandwidth log of the jobs in this job
 		graphs. See write_lat_log for behaviour of given
 		filename. For this option, the suffix is _bw.x.log, where
 		x is the index of the job (1..N, where N is the number of
-		jobs).
+		jobs). If 'per_job_logs' is false, then the filename will not
+		include the job index.
 
 write_lat_log=str Same as write_bw_log, except that this option stores io
 		submission, completion, and total latencies instead. If no
@@ -1453,13 +1484,17 @@ write_lat_log=str Same as write_bw_log, except that this option stores io
 		The actual log names will be foo_slat.x.log, foo_clat.x.log,
 		and foo_lat.x.log, where x is the index of the job (1..N,
 		where N is the number of jobs). This helps fio_generate_plot
-		fine the logs automatically.
+		fine the logs automatically. If 'per_job_logs' is false, then
+		the filename will not include the job index.
+
 
 write_iops_log=str Same as write_bw_log, but writes IOPS. If no filename is
 		given with this option, the default filename of
 		"jobname_type.x.log" is used,where x is the index of the job
 		(1..N, where N is the number of jobs). Even if the filename
-		is given, fio will still append the type of log.
+		is given, fio will still append the type of log. If
+		'per_job_logs' is false, then the filename will not include
+		the job index.
 
 log_avg_msec=int By default, fio will log an entry in the iops, latency,
 		or bw log for every IO that completes. When writing to the
@@ -2010,6 +2045,7 @@ before it can be used with this format. The offset and length are given in
 bytes. The action can be one of these:
 
 wait       Wait for 'offset' microseconds. Everything below 100 is discarded.
+	   The time is relative to the previous wait statement.
 read       Read 'length' bytes beginning from 'offset'
 write      Write 'length' bytes beginning from 'offset'
 sync       fsync() the file