Add 'allow_mounted_write' option

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index bb29826428574a77f0352e279155c4b6adb2cea0..ab0250cb60e6d84cde61f67916f8b48cef6ee843 100644 (file)
--- 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.
 
 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.
 
 randseed=int   Seed the random number generators based on this seed value, to
                be able to control what sequence of output is being generated.


@@ -1198,6 +1199,17 @@ 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.
 
                        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
 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


@@ -1433,6 +1445,16 @@ 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.
 
                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
 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 +1462,8 @@ 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
                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
 
 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 +1476,17 @@ 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
                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
 
 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
 
 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