X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=HOWTO;h=24171e9b2f3ef7feeae341aa870155871726673c;hb=a31041eaf5a306b5f6ad3dd14b60da6212775037;hp=21ba96033c283d0742f9191cc76ef97cf969277d;hpb=cd14cc1079771ece34fce5b30d47c7b273ee56e5;p=fio.git diff --git a/HOWTO b/HOWTO index 21ba9603..24171e9b 100644 --- a/HOWTO +++ b/HOWTO @@ -314,6 +314,8 @@ ioengine=str Defines how the job issues io to the file. The following sync Basic read(2) or write(2) io. lseek(2) is used to position the io location. + psync Basic pread(2) or pwrite(2) io. + libaio Linux native asynchronous io. posixaio glibc posix asynchronous io. @@ -347,7 +349,7 @@ ioengine=str Defines how the job issues io to the file. The following netsplice Like net, but uses splice/vmsplice to map data and send/receive. - cpu Doesn't transfer any data, but burns CPU + cpuio Doesn't transfer any data, but burns CPU cycles according to the cpuload= and cpucycle= options. Setting cpuload=85 will cause that job to do nothing but burn @@ -569,6 +571,9 @@ 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: @@ -592,6 +597,19 @@ verify=str If writing to a file, fio can verify the file contents 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. @@ -617,13 +635,10 @@ verify_interval=siint Write the verification header at a finer granularity size of header_interval. blocksize should divide this evenly. -verify_pattern=int If set, fio will fill the io buffers with this - pattern. Fio defaults to filling with totally random - bytes, but sometimes it's interesting to fill with a known - pattern for io verification purposes. Depending on the - width of the pattern, fio will fill 1/2/3/4 bytes of the - buffer at the time. The verify_pattern cannot be larger than - a 32-bit quantity. +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 @@ -743,7 +758,7 @@ 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%, @@ -774,7 +789,9 @@ 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