files between threads in a job or several jobs, specify
a filename for each of them to override the default. If
the ioengine used is 'net', the filename is the host, port,
- and protocol to use in the format of =host/port/protocol.
+ and protocol to use in the format of =host,port,protocol.
See ioengine=net for more. If the ioengine is file based, you
can specify a number of files by separating the names with a
':' colon. So if you wanted a job to open /dev/sda and /dev/sdb
libaio Linux native asynchronous io. Note that Linux
may only support queued behaviour with
non-buffered IO (set direct=1 or buffered=0).
- This engine also has a sub-option,
- userspace_reap. To set it, use
- ioengine=libaio:userspace_reap. Normally, with
- the libaio engine in use, fio will use the
- io_getevents system call to reap newly returned
- events. With this flag turned on, the AIO ring
- will be read directly from user-space to reap
- events. The reaping mode is only enabled when
- polling for a minimum of 0 events (eg when
- iodepth_batch_complete=0).
+ This engine defines engine specific options.
posixaio glibc posix asynchronous io.
itself and for debugging/testing purposes.
net Transfer over the network to given host:port.
- 'filename' must be set appropriately to
- filename=host/port/protocol regardless of send
- or receive, if the latter only the port
- argument is used. 'host' may be an IP address
- or hostname, port is the port number to be used,
- and protocol may be 'udp' or 'tcp'. If no
- protocol is given, TCP is used.
+ Depending on the protocol used, the hostname,
+ port, listen and filename options are used to
+ specify what sort of connection to make, while
+ the protocol option determines which protocol
+ will be used.
+ This engine defines engine specific options.
netsplice Like net, but uses splice/vmsplice to
map data and send/receive.
+ This engine defines engine specific options.
cpuio Doesn't transfer any data, but burns CPU
cycles according to the cpuload= and
bwavgtime=int Average the calculated bandwidth over the given time. Value
is specified in milliseconds.
+iopsavgtime=int Average the calculated IOPS over the given time. Value
+ is specified in milliseconds.
+
create_serialize=bool If true, serialize the file creating for the jobs.
This may be handy to avoid interleaving of data
files, which may greatly depend on the filesystem
verify_dump=bool If set, dump the contents of both the original data
block and the data block we read off disk to files. This
allows later analysis to inspect just what kind of data
- corruption occurred. On by default.
+ corruption occurred. Off by default.
verify_async=int Fio will normally verify IO inline from the submitting
thread. This option takes an integer describing how many
and foo_lat.log. This helps fio_generate_plot fine the logs
automatically.
+write_bw_log=str If given, write an IOPS log of the jobs in this job
+ file. See write_bw_log.
+
lockmem=int Pin down the specified amount of memory with mlock(2). Can
potentially be used instead of removing memory or booting
with less memory to simulate a smaller amount of memory.
gid=int Set group ID, see uid.
+In addition, there are some parameters which are only valid when a specific
+ioengine is in use. These are used identically to normal parameters, with the
+caveat that when used on the command line, they must come after the ioengine
+that defines them is selected.
+
+[libaio] userspace_reap Normally, with the libaio engine in use, fio will use
+ the io_getevents system call to reap newly returned events.
+ With this flag turned on, the AIO ring will be read directly
+ from user-space to reap events. The reaping mode is only
+ enabled when polling for a minimum of 0 events (eg when
+ iodepth_batch_complete=0).
+
+[netsplice] hostname=str
+[net] hostname=str The host name or IP address to use for TCP or UDP based IO.
+ If the job is a TCP listener or UDP reader, the hostname is not
+ used and must be omitted.
+
+[netsplice] port=int
+[net] port=int The TCP or UDP port to bind to or connect to.
+
+[netsplice] protocol=str
+[netsplice] proto=str
+[net] protocol=str
+[net] proto=str The network protocol to use. Accepted values are:
+
+ tcp Transmission control protocol
+ udp Unreliable datagram protocol
+ unix UNIX domain socket
+
+ When the protocol is TCP or UDP, the port must also be given,
+ as well as the hostname if the job is a TCP listener or UDP
+ reader. For unix sockets, the normal filename option should be
+ used and the port is invalid.
+
+[net] listen For TCP network connections, tell fio to listen for incoming
+ connections rather than initiating an outgoing connection. The
+ hostname must be omitted if this option is used.
+
+
6.0 Interpreting the output
---------------------------
Split up, the format is as follows:
- version, jobname, groupid, error
+ terse version, fio version, jobname, groupid, error
READ status:
- Total IO (KB), bandwidth (KB/sec), runtime (msec)
+ Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
Submission latency: min, max, mean, deviation
Completion latency: min, max, mean, deviation
+ Completion latency percentiles: 20 fields (see below)
Total latency: min, max, mean, deviation
Bw: min, max, aggregate percentage of total, mean, deviation
WRITE status:
- Total IO (KB), bandwidth (KB/sec), runtime (msec)
+ Total IO (KB), bandwidth (KB/sec), IOPS, runtime (msec)
Submission latency: min, max, mean, deviation
Completion latency: min, max, mean, deviation
+ Completion latency percentiles: 20 fields (see below)
Total latency: min, max, mean, deviation
Bw: min, max, aggregate percentage of total, mean, deviation
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
IO latencies milliseconds: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, 2000, >=2000
+ Disk utilization: Disk name, Read ios, write ios,
+ Read merges, write merges,
+ Read ticks, write ticks,
+ Time spent in queue, disk utilization percentage
Additional Info (dependant on continue_on_error, default off): total # errors, first error code
Additional Info (dependant on description being set): Text description
+Completion latency percentiles can be a grouping of up to 20 sets, so
+for the terse output fio writes all of them. Each field will look like this:
+
+ 1.00%=6112
+
+which is the Xth percentile, and the usec latency associated with it.
+
+For disk utilization, all disks used by fio are shown. So for each disk
+there will be a disk utilization section.
+
8.0 Trace file format
---------------------
projects / fio.git / blobdiff