X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=fbc455d44797dda6e779f561f1fe77178862583e;hp=f74360dee4becc4298bf7e7b8685a284550e552d;hb=342f570e7367f62ef6acf6e849726030187612ac;hpb=046395d7ab181288d14737c1d0041e98328f473f diff --git a/HOWTO b/HOWTO index f74360de..fbc455d4 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 @@ -1325,6 +1333,29 @@ 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. @@ -1599,6 +1630,15 @@ _ 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