of IO buffers is defined by the other options related to buffer contents. The
setting can be any pattern of bytes, and can be prefixed with 0x for hex
values. It may also be a string, where the string must then be wrapped with
-"".
+"", e.g.:
+.RS
+.RS
+\fBbuffer_pattern\fR="abcd"
+.RS
+or
+.RE
+\fBbuffer_pattern\fR=-12
+.RS
+or
+.RE
+\fBbuffer_pattern\fR=0xdeadface
+.RE
+.LP
+Also you can combine everything together in any order:
+.LP
+.RS
+\fBbuffer_pattern\fR=0xdeadface"abcd"-12
+.RE
+.RE
.TP
.BI dedupe_percentage \fR=\fPint
If set, fio will generate this percentage of identical buffers when writing.
not async on that OS. Keep an eye on the IO depth distribution in the
fio output to verify that the achieved depth is as expected. Default: 1.
.TP
-.BI iodepth_batch \fR=\fPint
-Number of I/Os to submit at once. Default: \fBiodepth\fR.
+.BI iodepth_batch \fR=\fPint "\fR,\fP iodepth_batch_submit" \fR=\fPint
+This defines how many pieces of IO to submit at once. It defaults to 1
+which means that we submit each IO as soon as it is available, but can
+be raised to submit bigger batches of IO at the time. If it is set to 0
+the \fBiodepth\fR value will be used.
.TP
-.BI iodepth_batch_complete \fR=\fPint
+.BI iodepth_batch_complete_min \fR=\fPint "\fR,\fP iodepth_batch_complete" \fR=\fPint
This defines how many pieces of IO to retrieve at once. It defaults to 1 which
means that we'll ask for a minimum of 1 IO in the retrieval process from the
kernel. The IO retrieval will go on until we hit the limit set by
completed events before queuing more IO. This helps reduce IO latency, at the
cost of more retrieval system calls.
.TP
+.BI iodepth_batch_complete_max \fR=\fPint
+This defines maximum pieces of IO to
+retrieve at once. This variable should be used along with
+\fBiodepth_batch_complete_min\fR=int variable, specifying the range
+of min and max amount of IO which should be retrieved. By default
+it is equal to \fBiodepth_batch_complete_min\fR value.
+
+Example #1:
+.RS
+.RS
+\fBiodepth_batch_complete_min\fR=1
+.LP
+\fBiodepth_batch_complete_max\fR=<iodepth>
+.RE
+
+which means that we will retrieve at leat 1 IO and up to the
+whole submitted queue depth. If none of IO has been completed
+yet, we will wait.
+
+Example #2:
+.RS
+\fBiodepth_batch_complete_min\fR=0
+.LP
+\fBiodepth_batch_complete_max\fR=<iodepth>
+.RE
+
+which means that we can retrieve up to the whole submitted
+queue depth, but if none of IO has been completed yet, we will
+NOT wait and immediately exit the system call. In this example
+we simply do polling.
+.RE
+.TP
.BI iodepth_low \fR=\fPint
Low watermark indicating when to start filling the queue again. Default:
\fBiodepth\fR.
.B lfsr
Linear feedback shift register generator
.TP
+.B tausworthe64
+Strong 64-bit 2^258 cycle random number generator
+.TP
.RE
.P
Tausworthe is a strong random number generator, but it requires tracking on the
laid out or updated on disk, only that will be done. The actual job contents
are not executed.
.TP
+.BI allow_file_create \fR=\fPbool
+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.
+.TP
+.BI allow_mounted_write \fR=\fPbool
+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.
+.TP
.BI pre_read \fR=\fPbool
If this is given, files will be pre-read into memory before starting the given
IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is
Default: true.
.TP
.BI verify \fR=\fPstr
-Method of verifying file contents after each iteration of the job. Allowed
-values are:
+Method of verifying file contents after each iteration of the job. Each
+verification method also implies verification of special header, which is
+written to the beginning of each block. This header also includes meta
+information, like offset of the block, block number, timestamp when block
+was written, etc. \fBverify\fR=str can be combined with \fBverify_pattern\fR=str
+option. The allowed values are:
.RS
.RS
.TP
not supported by the system.
.TP
.B meta
-Write extra information about each I/O (timestamp, block number, etc.). The
-block number is verified. See \fBverify_pattern\fR as well.
+This option is deprecated, since now meta information is included in generic
+verification header and meta verification happens by default. For detailed
+information see the description of the \fBverify\fR=str setting. This option
+is kept because of compatibility's sake with old configurations. Do not use it.
+.TP
+.B 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 \fBverify_pattern\fR is verified.
.TP
.B null
Pretend to verify. Used for testing internals.
fio will fill 1/2/3/4 bytes of the buffer at the time(it can be either a
decimal or a hex number). The verify_pattern if larger than a 32-bit quantity
has to be a hex number that starts with either "0x" or "0X". Use with
-\fBverify\fP=meta.
+\fBverify\fP=str. Also, verify_pattern supports %o format, which means that for
+each block offset will be written and then verifyied back, e.g.:
+.RS
+.RS
+\fBverify_pattern\fR=%o
+.RE
+Or use combination of everything:
+.LP
+.RS
+\fBverify_pattern\fR=0xff%o"abcd"-21
+.RE
+.RE
.TP
.BI verify_fatal \fR=\fPbool
If true, exit the job on the first observed verification failure. Default:
from. Setting \fBreplay_redirect\fR causes all IOPS to be replayed onto the
single specified device regardless of the device it was recorded from.
.TP
+.BI replay_align \fR=\fPint
+Force alignment of IO offsets and lengths in a trace to this power of 2 value.
+.TP
+.BI replay_scale \fR=\fPint
+Scale sector offsets down by this factor when replaying traces.
+.TP
+.BI per_job_logs \fR=\fPbool
+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.
+.TP
.BI write_bw_log \fR=\fPstr
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 script uses gnuplot to turn these text files into nice
graphs. See \fBwrite_lat_log\fR for behaviour of given filename. For this
option, the postfix is _bw.x.log, where x is the index of the job (1..N,
-where N is the number of jobs)
+where N is the number of jobs). If \fBper_job_logs\fR is false, then the
+filename will not include the job index.
.TP
.BI write_lat_log \fR=\fPstr
Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. 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.
+append the type of log. If \fBper_job_logs\fR is false, then the filename will
+not include the job index.
.TP
.BI write_iops_log \fR=\fPstr
Same as \fBwrite_bw_log\fR, 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 \fBper_job_logs\fR is false,
+then the filename will not include the job index.
.TP
.BI log_avg_msec \fR=\fPint
By default, fio will log an entry in the iops, latency, or bw log for every
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