ceph pg 计算方法 python

import math

pow_threshold = 0.25

def nearest_pow2(size):
    val = math.pow(2,round(math.log(size)/math.log(2)))
    if val < size * (1-pow_threshold):
        val *=2
    return val

def update_pg_count(osd_num,size,pg_osd=100,pre_data=0.1):

    min_val = nearest_pow2(math.floor(osd_num/size)+1)

    if min_val < osd_num:
        min_val *= 2
    calc_val = nearest_pow2(math.floor(pg_osd*osd_num*pre_data)/(100*size))

    if min_val > calc_val:
        return min_val
    else:
        return calc_val


print(int(update_pg_count(100,3,100,0.1)))