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.
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
(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.
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
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%,
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