打开fio的log：
1.10. Command line options （link）
--debug=type
Enable verbose tracing type of various fio actions. May be all for all types or individual types separated by a comma (e.g. --debug=file,mem will enable file and memory debugging). Currently, additional logging is available for:
process
Dump info related to processes.
file
Dump info related to file actions.
command:
fio --bs=8k --debug=file --output-format=json+ --direct=1 --output=/output/fio-randread-8k.json /input/fio-randread.job
output:
file 58 add file fio-randwrite
file 58 resize file array to 1 files
file 58 file 0x7f484ae0a0d0 "/testdir/fio-randwrite" added at 0
file 58 dup files: 1
file 58 setup files
file 58 get file size for 0x7f484ae0a2f0/0//testdir/fio-randwrite
file 58 layout unlink /testdir/fio-randwrite
file 58 open file /testdir/fio-randwrite, flags 41
file 60 trying file /testdir/fio-randwrite 0
file 60 fd open /testdir/fio-randwrite