Our currently DAG setup is consist of two 2016 exchange member servers along with a witness server.
Node 1 - DB1 (Active), DB2 (Passive), DB3 (Active), DB4 (Passive)
Node 2 - DB1 (Passive) DB2 (Active), DB3 (Passive), DB4 (Active)
Now according to our backup vendor (Veeam) when they are almost finished with backing up the server, Veeam send a signal to Microsoft VSS to basically truncated the exchange logs which then will truncate both the active and passive database.
In this case for our example, when node 1 is completely backup Veeam will then send a signal to Microsoft VSS provider to then truncate logs of both passive and active database. (Please correct me if I miss understood how exchange logs are truncated.)
It will then replicated the changes among the other DAG members. Therefore, my question and concern is from what Veeam indicated it is by Microsoft design that VSS provider can truncate passive database and then replicated to the primary source, is that truly the case?