Running fio with histogram output

# numpy and pandas required for fiologparser_hist.py:
dnf update && dnf install -y git python numpy python2-pandas gcc librbd1-devel

git clone https://github.com/axboe/fio.git && cd fio

# Increase max latency to ~9 minutes (default is 16 seconds):
sed -i.bak 's/^#define FIO_IO_U_PLAT_GROUP_NR 19\n/#define FIO_IO_U_PLAT_GROUP_NR 24/g' stat.h

make fio
cd tools/hist

# fio command for CEPH cluster as used by CBT, with histogram parameters added:
../../fio --ioengine=rbd --clientname=admin
  --pool=cbt-librbdfio --rbdname=cbt-librbdfio-`hostname -s`-0 \
  --invalidate=0  --rw=write --numjobs=1 --bs=4M --size 2048M \
  --name=librbdfio-`hostname -s`-0 --runtime=60s \
  --write_hist_log=z --log_hist_msec=1000 --log_hist_coarseness=3

# curl -L -O http://cronburg.com/fio/z_clat_hist.1.log # Example log file
./fiologparser_hist.py z_clat_hist.1.log