How to ensure Exchange 2016 Dag logs are truncating.

[Supraman]

Hello Everyone,

Our DAG is consist of a cluster of 2 member servers along with a witness server. An example of how our DAG look like in term of the active and passive database.

Node 1 - DB1 (Active), DB2 (Passive), DB3 (Active), DB4 (Passive)
Node 2 - DB1 (Passive) DB2 (Active), DB3 (Passive), DB4 (Active)

Now currently we are backing up the the exchange servers independently and application-awareness enable on both node 1 and 2. However; for node 1 we had set it to truncate the logs, whereas for node 2 we had put it to copy logs only. My I ask if this is best practice as we do not have a third node that is purely passive. From my understanding Veeam should be able to call upon Microsoft VSS writer to notified it to truncate the logs from either active or passive database and then it should replicated to the other DAG members. Please correct me if I have misunderstood what was Andreas had explain on his blog https://andyandthevms.com/exchange-dag- ... plication/ that backing up the passive database will also truncate the logs on the active.

[Mildur]

Hi Vinh

that backing up the passive database will also truncate the logs on the active.

Yes, that's what we write in our documentation. Unfortunately I don't have a DAG in my LAB to give it a test run.
Do you see any issue that logs are not truncated in your environment? How many log files are there in the DB Log Folder?

We have some Guides and Documentation for DAG backups:
Tips for DAG Exchange Backup and Replication in vSphere
Best Practice Guide
Veeam Agent - Backup of Database Availability Groups