AdS7 solutions of massive type IIA have been classified, and are dual to a large class of six-dimensional (1,0) SCFT's. The latter are amenable to tensor branch deformations, described by linear quivers of SU groups. Quivers and AdS vacua depend solely on the group theory data of the NS5-D6-D8 brane configurations engineering the field theories. This has allowed for a direct holographic match of their a conformal anomaly.

In this talk we will extend the match to cases where O6 and O8-planes are present, which are responsible for the introduction of SO and USp groups in the quivers. In all of them we show that the a anomaly computed in supergravity agrees with the holographic limit of the exact field theory result, which we extract from the M5 anomaly polynomial. Along the way, we construct special AdS7 vacua dual to nonperturbative F-theory configurations.