tidb ansible 部署方式环境检查过于严格，测试环境往往达不到标准，需调整一些参数才能部署成功。
基于tidb2.0版本需要调整的参数
[tidb@ansible01 tidb-ansible]$ vim ./roles/machine_benchmark/defaults/main.yml
---
fio_deploy_dir: "{{ tikv_data_dir }}/fio"
# fio randread iops
min_ssd_randread_iops: 400
# fio mixed randread and sequential write
min_ssd_mix_randread_iops: 100
min_ssd_mix_write_iops: 100
# fio mixed randread and sequential write lat
max_ssd_mix_randread_lat: 2500000
max_ssd_mix_write_lat: 300000
# fio test file size
benchmark_size: 10G
[tidb@ansible01 tidb-ansible]$ vim ./roles/machine_benchmark/defaults/main.yml
---
fio_deploy_dir: "{{ tikv_data_dir }}/fio"
# fio randread iops
min_ssd_randread_iops: 400
# fio mixed randread and sequential write
min_ssd_mix_randread_iops: 100
min_ssd_mix_write_iops: 100
# fio mixed randread and sequential write lat
max_ssd_mix_randread_lat: 250
max_ssd_mix_write_lat: 300
# fio test file size
benchmark_size: 10G