What is a reasonable value for annex.bloomcapacity in this situation and in what unit?

local annex keys: 670671
local annex size: 2.62 terabytes
annexed files in working tree: 1410199
size of annexed files in working tree: 3.52 terabytes
combined annex size of all repositories: 2.63 terabytes
annex sizes of repositories: 
    2.62 TB: b2e77041-584e-4699-947d-ef5004273901 -- pudong [here]
    7.39 GB: 42a53a13-7ad6-43a5-95ef-813d4f8c1a6f -- [batam_payload]
backend usage: 
    SHA256E: 1410199
bloom filter size: 32 mebibytes (appears too small for this repository; adjust annex.bloomcapacity)

I don't really understand what happens when the bloom filter is too small.