I have 2 nodes Exchange 2013 Cu 17 in DAG. When getting mailbox database copy status it shows that both active and passive copy is having "Unknown" in content index status. I was unable to update the database catalog since none of them has healthy copy.
I searched around few article and saw the following options that I could try:
Check if ContentSubmitters group exist in AD, if not then create it and assign Full control to administrators and network services accordingly. Restart Exchange search host services
Rebuild the database content indexes
As for option no.2, since my environment is a 2 node DAG, can I still rebuild the content index on Active node, and then update the database catalog on passive copy? Because what I can see people mostly saying that this solution is for standalone Exchange server which is not a member of DAG.