Hi, I think there's a minor issue in how pg_checksums validates state before checking the data.
The current patch simply does: if (ControlFile->data_checksum_version == 0 && mode == PG_MODE_CHECK) pg_fatal("data checksums are not enabled in cluster"); and that worked when the version was either 0 or 1. But now it can be also 2 or 3, for inprogress-on / inprogress-off, and if the cluster gets shut down at the right moment, that can end in the control file. It doesn't make sense to verify checksums in such cluster, pg_checksums should handle that as "off", i.e. error out. regards -- Tomas Vondra