X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=9a9f02a7bf6ec688a8bb5b546d6879a255de3990;hp=250bc582f548640a92087a6d2119962d5f63d81e;hb=26251d8d635bc9b9d31de2427095684b0c87b836;hpb=d01612f3ae2515eb035d0c4ce954d8cb167a0a61 diff --git a/HOWTO b/HOWTO index 250bc582..9a9f02a7 100644 --- a/HOWTO +++ b/HOWTO @@ -223,7 +223,8 @@ a string. The following types are used: str String. This is a sequence of alpha characters. time Integer with possible time suffix. In seconds unless otherwise specified, use eg 10m for 10 minutes. Accepts s/m/h for seconds, - minutes, and hours. + minutes, and hours, and accepts 'ms' (or 'msec') for milliseconds, + and 'us' (or 'usec') for microseconds. int SI integer. A whole number value, which may contain a suffix describing the base of the number. Accepted suffixes are k/m/g/t/p, meaning kilo, mega, giga, tera, and peta. The suffix is not case @@ -384,6 +385,11 @@ 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. +randseed=int Seed the random number generators based on this seed value, to + be able to control what sequence of output is being generated. + If not set, the random sequence depends on the randrepeat + setting. + use_os_rand=bool Fio can either use the random generator supplied by the OS to generator random offsets, or it can use it's own internal generator (based on Tausworthe). Default is to use the @@ -542,6 +548,11 @@ buffer_compress_chunk=int See buffer_compress_percentage. This alternate random and zeroed data throughout the IO buffer. +buffer_pattern=str If set, fio will fill the io buffers with this pattern. + If not set, the contents 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. + nrfiles=int Number of files to use for this job. Defaults to 1. openfiles=int Number of files to keep open at the same time. Defaults to @@ -881,6 +892,20 @@ rate_iops_min=int If fio doesn't meet this rate of IO, it will cause the job to exit. The same format as rate is used for read vs write separation. +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. + See latency_window and latency_percentile + +latency_window=int Used with latency_target to specify the sample window + that the job is run at varying queue depths to test the + performance. The value is given in microseconds. + +latency_percentile=float The percentage of IOs that must fall within the + criteria specified by latency_target and latency_window. If not + set, this defaults to 100.0, meaning that all IOs must be equal + or below to the value set by latency_target. + max_latency=int If set, fio will exit the job if it exceeds this maximum latency. It will exit with an ETIME error. @@ -903,6 +928,18 @@ cpus_allowed=str Controls the same options as cpumask, but it allows a text allows a range of CPUs. Say you wanted a binding to CPUs 1, 5, and 8-15, you would set cpus_allowed=1,5,8-15. +cpus_allowed_policy=str Set the policy of how fio distributes the CPUs + specified by cpus_allowed or cpumask. Two policies are + supported: + + shared All jobs will share the CPU set specified. + split Each job will get a unique CPU from the CPU set. + + 'shared' is the default behaviour, if the option isn't + specified. If split is specified, then fio will will assign + one cpu per job. If not enough CPUs are given for the jobs + listed, then fio will roundrobin the CPUs in the set. + numa_cpu_nodes=str Set this job running on spcified NUMA nodes' CPUs. The arguments allow comma delimited list of cpu numbers, A-B ranges, or 'all'. Note, to enable numa options support, @@ -1044,6 +1081,13 @@ loops=int Run the specified number of iterations of this job. Used to repeat the same workload a given number of times. Defaults to 1. +verify_only Do not perform specified workload---only verify data still + matches previous invocation of this workload. This option + allows one to check data multiple times at a later date + without overwriting it. This option makes sense only for + workloads that write data, and does not support workloads + with the time_based option set. + do_verify=bool Run the verify phase after a write phase. Only makes sense if verify is set. Defaults to 1. @@ -1074,6 +1118,10 @@ verify=str If writing to a file, fio can verify the file contents crc7 Use a crc7 sum of the data area and store it in the header of each block. + xxhash Use xxhash as the checksum function. Generally + the fastest software checksum that fio + supports. + sha512 Use sha512 as the checksum function. sha256 Use sha256 as the checksum function. @@ -1082,7 +1130,9 @@ verify=str If writing to a file, fio can verify the file contents meta Write extra information about each io (timestamp, block number etc.). The block - number is verified. See also verify_pattern. + number is verified. The io sequence number is + verified for workloads that write data. + See also verify_pattern. null Only pretend to verify. Useful for testing internals with ioengine=null, not for much @@ -1472,7 +1522,9 @@ that defines them is selected. [net] proto=str The network protocol to use. Accepted values are: tcp Transmission control protocol + tcpv6 Transmission control protocol V6 udp User datagram protocol + udpv6 User datagram protocol V6 unix UNIX domain socket When the protocol is TCP or UDP, the port must also be given,