X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=d185f8a2944a36d3c45ad33810cdc9dd42c56bd2;hp=8cb849c7c6edad0ddf70294d98f3084cd2894a5a;hb=81887d5dcd608492e59ed3fb2ac8fcb463223120;hpb=546a9142511875524850ac92776184fd9fb7196e diff --git a/HOWTO b/HOWTO index 8cb849c7..d185f8a2 100644 --- a/HOWTO +++ b/HOWTO @@ -170,7 +170,8 @@ Some parameters take an option of a given type, such as an integer or a string. The following types are used: str String. This is a sequence of alpha characters. -int Integer. A whole number value, can be negative. +int Integer. A whole number value, can be negative. If prefixed with + 0x, the integer is assumed to be of base 16 (hexidecimal). siint SI integer. A whole number value, which may contain a postfix describing the base of the number. Accepted postfixes are k/m/g, meaning kilo, mega, and giga. So if you want to specify 4096, @@ -568,6 +569,9 @@ 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. +do_verify=bool Run the verify phase after a write phase. Only makes sense if + verify is set. Defaults to 1. + verify=str If writing to a file, fio can verify the file contents after each iteration of the job. The allowed values are: @@ -587,6 +591,23 @@ 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. + sha512 Use sha512 as the checksum function. + + sha256 Use sha256 as the checksum function. + + meta Write extra information about each io + (timestamp, block number etc.). The block + number is verified. + + pattern Fill the IO buffers with a specific pattern, + that we can use to verify. Depending on the + width of the pattern, fio will fill 1/2/3/4 + bytes of the buffer at the time. The pattern + cannot be larger than a 32-bit quantity. The + given pattern is given as a postfix to this + option, ala: verify=pattern:0x5a. It accepts + both hex and dec values. + null Only pretend to verify. Useful for testing internals with ioengine=null, not for much else. @@ -603,14 +624,19 @@ verifysort=bool If set, fio will sort written verify blocks when it deems fast IO where the red-black tree sorting CPU time becomes significant. -header_offset=siint Swap the verification header with data somewhere else +verify_offset=siint Swap the verification header with data somewhere else in the block before writing. Its swapped back before verifying. -header_interval=siint Write the verification header at a finer granularity +verify_interval=siint Write the verification header at a finer granularity than the blocksize. It will be written for chunks the size of header_interval. blocksize should divide this evenly. + +verify_fatal=bool Normally fio will keep checking the entire contents + before quitting on a block verification failure. If this + option is set, fio will exit the job on the first observed + failure. stonewall Wait for preceeding jobs in the job file to exit, before starting this one. Can be used to insert serialization @@ -730,7 +756,7 @@ Client1 (g=0): err= 0: slat (msec): min= 0, max= 136, avg= 0.03, stdev= 1.92 clat (msec): min= 0, max= 631, avg=48.50, stdev=86.82 bw (KiB/s) : min= 0, max= 1196, per=51.00%, avg=664.02, stdev=681.68 - cpu : usr=1.49%, sys=0.25%, ctx=7969 + cpu : usr=1.49%, sys=0.25%, ctx=7969, majf=0, minf=17 IO depths : 1=0.1%, 2=0.3%, 4=0.5%, 8=99.0%, 16=0.0%, 32=0.0%, >32=0.0% issued r/w: total=0/32768, short=0/0 lat (msec): 2=1.6%, 4=0.0%, 10=3.2%, 20=12.8%, 50=38.4%, 100=24.8%, @@ -761,7 +787,9 @@ runt= The runtime of that thread only really useful if the threads in this group are on the same disk, since they are then competing for disk access. cpu= CPU usage. User and system time, along with the number - of context switches this thread went through. + of context switches this thread went through, usage of + system and user time, and finally the number of major + and minor page faults. IO depths= The distribution of io depths over the job life time. The numbers are divided into powers of 2, so for example the 16= entries includes depths up to that value but higher