X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=1c4b308cf3df9bd33d75306cb3e0e2dfd8df4a40;hp=7db7b8929a21a46b971bb9a45f5a774e721f96a1;hb=69bdd6badc47775443413405e1aea4abe9e570c9;hpb=3d434057fd4c20c2b1216d9696c4fed9f7d8c4dd diff --git a/HOWTO b/HOWTO index 7db7b892..1c4b308c 100644 --- a/HOWTO +++ b/HOWTO @@ -81,7 +81,7 @@ $ fio job_file and it will start doing what the job_file tells it to do. You can give more than one job file on the command line, fio will serialize the running of those files. Internally that is the same as using the 'stonewall' -parameter described the the parameter section. +parameter described in the parameter section. If the job file contains only one job, you may as well just give the parameters on the command line. The command line parameters are identical @@ -424,12 +424,20 @@ size=int The total size of file io for this job. Fio will run until Unless specific nrfiles and filesize options are given, fio will divide this size between the available files specified by the job. If not set, fio will use the full - size of the given files or devices. If the the files - do not exist, size must be given. It is also possible to - give size as a percentage between 1 and 100. If size=20% - is given, fio will use 20% of the full size of the given + size of the given files or devices. If the files do not + exist, size must be given. It is also possible to give + size as a percentage between 1 and 100. If size=20% is + given, fio will use 20% of the full size of the given files or devices. +io_limit=int Normally fio operates within the region set by 'size', which + means that the 'size' option sets both the region and size of + IO to be performed. Sometimes that is not what you want. With + this option, it is possible to define just the amount of IO + that fio should do. For instance, if 'size' is set to 20G and + 'io_limit' is set to 5G, fio will perform IO within the first + 20G but exit when 5G have been done. + filesize=int Individual file sizes. May be a range, in which case fio will select sizes for files at random within the given range and limited to 'size' in total (if that is given). If not @@ -728,11 +736,12 @@ offset=int Start io at the given offset in the file. The data before caps the file size at real_size - offset. offset_increment=int If this is provided, then the real offset becomes - the offset + offset_increment * thread_number, where the - thread number is a counter that starts at 0 and is incremented - for each job. This option is useful if there are several jobs - which are intended to operate on a file in parallel in disjoint - segments, with even spacing between the starting points. + offset + offset_increment * thread_number, where the thread + number is a counter that starts at 0 and is incremented for + each sub-job (i.e. when numjobs option is specified). This + option is useful if there are several jobs which are intended + to operate on a file in parallel disjoint segments, with + even spacing between the starting points. number_ios=int Fio will normally perform IOs until it has exhausted the size of the region set by size=, or if it exhaust the allocated @@ -1299,7 +1308,9 @@ write_bw_log=str If given, write a bandwidth log of the jobs in this job jobs in their lifetime. The included fio_generate_plots script uses gnuplot to turn these text files into nice graphs. See write_lat_log for behaviour of given - filename. For this option, the suffix is _bw.log. + filename. For this option, the suffix is _bw.x.log, where + x is the index of the job (1..N, where N is the number of + jobs). write_lat_log=str Same as write_bw_log, except that this option stores io submission, completion, and total latencies instead. If no @@ -1309,14 +1320,16 @@ write_lat_log=str Same as write_bw_log, except that this option stores io write_lat_log=foo - The actual log names will be foo_slat.log, foo_clat.log, - and foo_lat.log. This helps fio_generate_plot fine the logs - automatically. + The actual log names will be foo_slat.x.log, foo_clat.x.log, + and foo_lat.x.log, where x is the index of the job (1..N, + where N is the number of jobs). This helps fio_generate_plot + fine the logs automatically. write_iops_log=str Same as write_bw_log, but writes IOPS. If no filename is given with this option, the default filename of - "jobname_type.log" is used. Even if the filename is given, - fio will still append the type of log. + "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. log_avg_msec=int By default, fio will log an entry in the iops, latency, or bw log for every IO that completes. When writing to the @@ -1325,6 +1338,29 @@ log_avg_msec=int By default, fio will log an entry in the iops, latency, specified period of time, reducing the resolution of the log. Defaults to 0. +log_offset=int If this is set, the iolog options will include the byte + offset for the IO entry as well as the other data values. + +log_compression=int If this is set, fio will compress the IO logs as + it goes, to keep the memory footprint lower. When a log + reaches the specified size, that chunk is removed and + compressed in the background. Given that IO logs are + fairly highly compressible, this yields a nice memory + savings for longer runs. The downside is that the + compression will consume some background CPU cycles, so + it may impact the run. This, however, is also true if + the logging ends up consuming most of the system memory. + So pick your poison. The IO logs are saved normally at the + end of a run, by decompressing the chunks and storing them + in the specified log file. This feature depends on the + availability of zlib. + +log_store_compressed=bool If set, and log_compression is also set, + fio will store the log files in a compressed format. They + can be decompressed with fio, using the --inflate-log + command line parameter. The files will be stored with a + .fz suffix. + 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. @@ -1505,6 +1541,8 @@ that defines them is selected. [cpu] cpuchunks=int Split the load into cycles of the given time. In microseconds. +[cpu] exit_on_io_done=bool Detect when IO threads are done, then exit. + [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 @@ -1597,6 +1635,15 @@ _ Thread reaped, or X Thread reaped, exited with an error. K Thread reaped, exited due to signal. +Fio will condense the thread string as not to take up more space on the +command line as is needed. For instance, if you have 10 readers and 10 +writers running, the output would look like this: + +Jobs: 20 (f=20): [R(10),W(10)] [4.0% done] [2103MB/0KB/0KB /s] [538K/0/0 iops] [eta 57m:36s] + +Fio will still maintain the ordering, though. So the above means that jobs +1..10 are readers, and 11..20 are writers. + The other values are fairly self explanatory - number of threads currently running and doing io, rate of io since last check (read speed listed first, then write speed), and the estimated completion percentage