-------------------------
fio also supports environment variable expansion in job files. Any
-substring of the form "${VARNAME}" as part of an option value (in other
+sub-string of the form "${VARNAME}" as part of an option value (in other
words, on the right of the `='), will be expanded to the value of the
environment variable called VARNAME. If no such environment variable
is defined, or VARNAME is the empty string, the empty string will be
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 "".
+ be wrapped with "", e.g.:
+
+ buffer_pattern="abcd"
+ or
+ buffer_pattern=-12
+ or
+ buffer_pattern=0xdeadface
+
+ Also you can combine everything together in any order:
+ buffer_pattern=0xdeadface"abcd"-12
dedupe_percentage=int If set, fio will generate this percentage of
identical buffers when writing. These buffers will be
iodepth_batch=int 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.
+ bigger batches of IO at the time. If it is set to 0 the iodepth
+ value will be used.
+iodepth_batch_complete_min=int
iodepth_batch_complete=int 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
events before queuing more IO. This helps reduce
IO latency, at the cost of more retrieval system calls.
+iodepth_batch_complete_max=int This defines maximum pieces of IO to
+ retrieve at once. This variable should be used along with
+ iodepth_batch_complete_min=int variable, specifying the range
+ of min and max amount of IO which should be retrieved. By default
+ it is equal to iodepth_batch_complete_min value.
+
+ Example #1:
+
+ iodepth_batch_complete_min=1
+ iodepth_batch_complete_max=<iodepth>
+
+ 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:
+
+ iodepth_batch_complete_min=0
+ iodepth_batch_complete_max=<iodepth>
+
+ 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.
+
iodepth_low=int The low water mark indicating when to start filling
the queue again. Defaults to the same as iodepth, meaning
that fio will attempt to keep the queue full at all times.
fdatasync=int Like fsync= but uses fdatasync() to only sync data and not
metadata blocks.
- In FreeBSD and Windows there is no fdatasync(), this falls back to
- using fsync()
+ In FreeBSD and Windows there is no fdatasync(), this falls back
+ to using fsync()
sync_file_range=str:val Use sync_file_range() for every 'val' number of
write operations. Fio will track range of writes that
will only limit writes (to 500KB/sec), the latter will only
limit reads.
-ratemin=int Tell fio to do whatever it can to maintain at least this
+rate_min=int Tell fio to do whatever it can to maintain at least this
bandwidth. Failing to meet this requirement, will cause
the job to exit. The same format as rate is used for
read vs write separation.
the job to exit. The same format as rate is used for read vs
write separation.
+rate_process=str This option controls how fio manages rated IO
+ submissions. The default is 'linear', which submits IO in a
+ linear fashion with fixed delays between IOs that gets
+ adjusted based on IO completion rates. If this is set to
+ 'poisson', fio will submit IO based on a more real world
+ random request flow, known as the Poisson process
+ (https://en.wikipedia.org/wiki/Poisson_process). The lambda
+ will be 10^6 / IOPS for the given workload.
+
latency_target=int If set, fio will attempt to find the max performance
point that the given workload will run at while maintaining a
latency below this target. The values is given in microseconds.
max_latency=int If set, fio will exit the job if it exceeds this maximum
latency. It will exit with an ETIME error.
-ratecycle=int Average bandwidth for 'rate' and 'ratemin' over this number
+rate_cycle=int Average bandwidth for 'rate' and 'rate_min' over this number
of milliseconds.
cpumask=int Set the CPU affinity of this job. The parameter given is a
backing. Append filename after mmaphuge, ala
mem=mmaphuge:/hugetlbfs/file
+ mmapshared Same as mmap, but use a MMAP_SHARED
+ mapping.
+
The area allocated is a function of the maximum allowed
bs size for the job, multiplied by the io depth given. Note
that for shmhuge and mmaphuge to work, the system must have
verify is set. Defaults to 1.
verify=str If writing to a file, fio can verify the file contents
- after each iteration of the job. The allowed values are:
+ 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.
+ verify=str can be combined with verify_pattern=str option.
+ The allowed values are:
md5 Use an md5 sum of the data area and store
it in the header of each block.
sha1 Use optimized sha1 as the checksum function.
- meta Write extra information about each io
- (timestamp, block number etc.). The block
- number is verified. The io sequence number is
- verified for workloads that write data.
- See also verify_pattern.
+ meta 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 verify=str setting. This option is kept because of
+ compatibility's sake with old configurations. Do not use it.
+
+ 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
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 verify=meta.
+ with verify=str. Also, verify_pattern supports %o format,
+ which means that for each block offset will be written and
+ then verifyied back, e.g.:
+
+ verify_pattern=%o
+
+ Or use combination of everything:
+ verify_pattern=0xff%o"abcd"-12
verify_fatal=bool Normally fio will keep checking the entire contents
before quitting on a block verification failure. If this
terse version, fio version, jobname, groupid, error
READ status:
Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
- Submission latency: min, max, mean, deviation (usec)
- Completion latency: min, max, mean, deviation (usec)
+ Submission latency: min, max, mean, stdev (usec)
+ Completion latency: min, max, mean, stdev (usec)
Completion latency percentiles: 20 fields (see below)
- Total latency: min, max, mean, deviation (usec)
- Bw (KB/s): min, max, aggregate percentage of total, mean, deviation
+ Total latency: min, max, mean, stdev (usec)
+ Bw (KB/s): min, max, aggregate percentage of total, mean, stdev
WRITE status:
Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
- Submission latency: min, max, mean, deviation (usec)
- Completion latency: min, max, mean, deviation (usec)
+ Submission latency: min, max, mean, stdev (usec)
+ Completion latency: min, max, mean, stdev(usec)
Completion latency percentiles: 20 fields (see below)
- Total latency: min, max, mean, deviation (usec)
- Bw (KB/s): min, max, aggregate percentage of total, mean, deviation
+ Total latency: min, max, mean, stdev (usec)
+ Bw (KB/s): min, max, aggregate percentage of total, mean, stdev
CPU usage: user, system, context switches, major faults, minor faults
IO depths: <=1, 2, 4, 8, 16, 32, >=64
IO latencies microseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000
projects / fio.git / blobdiff