  A search for the $b\bar b$ decay of the Standard Model Higgs boson produced
through vector-boson fusion is presented. Three mutually exclusive channels are
considered: two all-hadronic channels and a photon-associated channel. Results
are reported from the analysis of up to 30.6 fb$^{-1}$ of $pp$ data at
$\sqrt{s} = 13$ $\mathrm{TeV}$ collected with the ATLAS detector at the LHC.
The measured signal strength relative to the Standard Model prediction from the
combined analysis is $2.5^{+1.4}_{-1.3}$ for inclusive Higgs boson production
and $3.0^{+1.7}_{-1.6}$ for vector-boson fusion production only.
