X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=32e5d668c89e42efec4704b2db8686afc32e17c2;hp=ec7005fe5b44e1c70c2ff6e2195849599a24e0ca;hb=856b09c838bfd45a9d6d87a1ab03458c9b058d56;hpb=eebd2f2d8a022a248acac5685f73665aa0c6ee99 diff --git a/HOWTO b/HOWTO index ec7005fe..32e5d668 100644 --- a/HOWTO +++ b/HOWTO @@ -61,7 +61,7 @@ bottom, it contains the following basic parameters: Num threads How many threads or processes should we spread this workload over. - + The above are the basic parameters defined for a workload, in addition there's a multitude of parameters that modify other aspects of how this job behaves. @@ -274,11 +274,14 @@ filename=str Fio normally makes up a filename based on the job name, as the two working files, you would use filename=/dev/sda:/dev/sdb. On Windows, disk devices are accessed as \\.\PhysicalDrive0 for the first device, \\.\PhysicalDrive1 - for the second etc. If the wanted filename does need to - include a colon, then escape that with a '\' character. - For instance, if the filename is "/dev/dsk/foo@3,0:c", - then you would use filename="/dev/dsk/foo@3,0\:c". - '-' is a reserved name, meaning stdin or stdout. Which of the + for the second etc. + Note: Windows and FreeBSD prevent write access to areas of the disk + containing in-use data (e.g. filesystems). + If the wanted filename does need to include a colon, then escape that + with a '\' character. + For instance, if the filename is "/dev/dsk/foo@3,0:c", + then you would use filename="/dev/dsk/foo@3,0\:c". + '-' is a reserved name, meaning stdin or stdout. Which of the two depends on the read/write direction set. opendir=str Tell fio to recursively add any file it can find in this @@ -716,6 +719,25 @@ rwmixwrite=int How large a percentage of the mix should be writes. If both if fio is asked to limit reads or writes to a certain rate. If that is the case, then the distribution may be skewed. +random_distribution=str:float By default, fio will use a completely uniform + random distribution when asked to perform random IO. Sometimes + it is useful to skew the distribution in specific ways, + ensuring that some parts of the data is more hot than others. + fio includes the following distribution models: + + random Uniform random distribution + zipf Zipf distribution + pareto Pareto distribution + + When using a zipf or pareto distribution, an input value + is also needed to define the access pattern. For zipf, this + is the zipf theta. For pareto, it's the pareto power. Fio + includes a test program, genzipf, that can be used visualize + what the given input values will yield in terms of hit rates. + If you wanted to use zipf with a theta of 1.2, you would use + random_distribution=zipf:1.2 as the option. If a non-uniform + model is used, fio will disable use of the random map. + norandommap Normally fio will cover every block of the file when doing random IO. If this option is given, fio will just get a new random offset without looking at past io history. This @@ -780,6 +802,9 @@ 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 seperation. +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 of milliseconds. @@ -799,6 +824,24 @@ 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. +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, + export the following environment variables, + export EXTFLAGS+=" -DFIO_HAVE_LIBNUMA " + export EXTLIBS+=" -lnuma " + +numa_mem_policy=str Set this job's memory policy and corresponding NUMA + nodes. Format of the argements: + [:] + `mode' is one of the following memory policy: + default, prefer, bind, interleave, local + For `default' and `local' memory policy, no node is + needed to be specified. + For `prefer', only one node is allowed. + For `bind' and `interleave', it allow comma delimited + list of numbers, A-B ranges, or 'all'. + startdelay=time Start this job the specified number of seconds after fio has started. Only useful if the job file contains several jobs, and you want to delay starting some jobs to a certain @@ -1046,29 +1089,29 @@ verify_backlog_batch=int Control how many blocks fio will verify less than verify_backlog then not all blocks will be verified, if verify_backlog_batch is larger than verify_backlog, some blocks will be verified more than once. - + stonewall wait_for_previous Wait for preceeding jobs in the job file to exit, before starting this one. Can be used to insert serialization points in the job file. A stone wall also implies starting a new reporting group. -new_group Start a new reporting group. If this option isn't given, - jobs in a file will be part of the same reporting group - unless separated by a stone wall (or if it's a group - by itself, with the numjobs option). +new_group Start a new reporting group. See: group_reporting. numjobs=int Create the specified number of clones of this job. May be used to setup a larger number of threads/processes doing - the same thing. We regard that grouping of jobs as a - specific group. - -group_reporting If 'numjobs' is set, it may be interesting to display - statistics for the group as a whole instead of for each - individual job. This is especially true of 'numjobs' is - large, looking at individual thread/process output quickly - becomes unwieldy. If 'group_reporting' is specified, fio - will show the final report per-group instead of per-job. + the same thing. Each thread is reported separately; to see + statistics for all clones as a whole, use group_reporting in + conjunction with new_group. + +group_reporting It may sometimes be interesting to display statistics for + groups of jobs as a whole instead of for each individual job. + This is especially true if 'numjobs' is used; looking at + individual thread/process output quickly becomes unwieldy. + To see the final report per-group instead of per-job, use + 'group_reporting'. Jobs in a file will be part of the same + reporting group, unless if separated by a stonewall, or by + using 'new_group'. thread fio defaults to forking jobs, however if this option is given, fio will use pthread_create(3) to create threads @@ -1092,7 +1135,7 @@ read_iolog=str Open an iolog with the specified file name and replay the for how to capture such logging data. For blktrace replay, the file needs to be turned into a blkparse binary data file first (blkparse -o /dev/null -d file_for_fio.bin). - + replay_no_stall=int When replaying I/O with read_iolog the default behavior is to attempt to respect the time stamps within the log and replay them with the appropriate delay between IOPS. By @@ -1248,6 +1291,19 @@ continue_on_error=str Normally fio will exit the job on the first observed 1 Backward-compatible alias for 'all'. +ignore_error=str Sometimes you want to ignore some errors during test + in that case you can specify error list for each error type. + ignore_error=READ_ERR_LIST,WRITE_ERR_LIST,VERIFY_ERR_LIST + errors for given error type is separated with ':'. Error + may be symbol ('ENOSPC', 'ENOMEM') or integer. + Example: + ignore_error=EAGAIN,ENOSPC:122 + This option will ignore EAGAIN from READ, and ENOSPC and + 122(EDQUOT) from WRITE. + +error_dump=bool If set dump every error even if it is non fatal, true + by default. If disabled only fatal error will be dumped + cgroup=str Add job to this control group. If it doesn't exist, it will be created. The system must have a mounted cgroup blkio mount point for this to work. If your system doesn't have it @@ -1315,7 +1371,7 @@ that defines them is selected. [net] proto=str The network protocol to use. Accepted values are: tcp Transmission control protocol - udp Unreliable datagram protocol + udp User datagram protocol unix UNIX domain socket When the protocol is TCP or UDP, the port must also be given, @@ -1329,7 +1385,7 @@ that defines them is selected. [e4defrag] donorname=str File will be used as a block donor(swap extents between files) [e4defrag] inplace=int - Configure donor file blocks allocation strategy + Configure donor file blocks allocation strategy 0(default): Preallocate donor's file on init 1 : allocate space immidietly inside defragment event, and free right after event @@ -1351,7 +1407,7 @@ Idle Run ---- --- P Thread setup, but not started. C Thread created. -I Thread initialized, waiting. +I Thread initialized, waiting or generating necessary data. p Thread running pre-reading file(s). R Running, doing sequential reads. r Running, doing random reads. @@ -1517,8 +1573,8 @@ Split up, the format is as follows: 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 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 @@ -1534,7 +1590,7 @@ there will be a disk utilization section. 8.0 Trace file format --------------------- -There are two trace file format that you can encounter. The older (v1) format +There are two trace file format that you can encounter. The older (v1) format is unsupported since version 1.20-rc3 (March 2008). It will still be described below in case that you get an old trace and want to understand it. @@ -1571,7 +1627,7 @@ filename action The filename is given as an absolute path. The action can be one of these: add Add the given filename to the trace -open Open the file with the given filename. The filename has to have +open Open the file with the given filename. The filename has to have been added with the add action before. close Close the file with the given filename. The file has to have been opened before. @@ -1582,7 +1638,7 @@ The file io action format: filename action offset length The filename is given as an absolute path, and has to have been added and opened -before it can be used with this format. The offset and length are given in +before it can be used with this format. The offset and length are given in bytes. The action can be one of these: wait Wait for 'offset' microseconds. Everything below 100 is discarded.