Our first job is to define what we mean by verify. By default, DRBD is somewhat minimal, and it has no default for the algorithm it should use for checksum comparisons. The verify-alg setting is a network-oriented value and defines how DRBD should compare data segments. We also know md5 as a widely-used checksum algorithm. Thus, we set the verify-alg in a net block within the resource definition for pg.
Afterwards, we need to reread the configuration files so that the verify-alg setting is defined for the verification step. By invoking drbdadm with the adjust parameter, it will read and apply any valid changes we made to /etc/drbd.d/pg.res. When we're ready, we can launch the verification process by calling drbdadm with the ...
