Using SQL Server 2017, can log backups be safely taken on primary when using Log Shipping or Availability Groups?

Question

We have a CommVault server taking log 15-minutely log backups of our primary (on-premise) DBs (combined with full nightlies), for point-in-time restores.

We want to enable high availability for DR fail-over to a cloud-based SQL Instance and we will be using either Log Shipping or Availability Groups.

This secondary instance will be truly passive so as not to incur additional licensing costs (i.e. we will not be able to take backups from it)

We are using SQL Server 2017 Standard Edition and, again for licensing cost reasons, won't be upgrading to Enterprise.

My question is - can CommVault continue to take its log backups for reliable point-in-time recovery and at the same time that either of the high availability options is enabled, or is there a risk of interference?

Answer 1

can CommVault continue to take its log backups for reliable point-in-time recovery and at the same time that either of the high availability options is enabled, or is there a risk of interference?

You can only have one log chain, so Log Shipping and your CommVault log backups will conflict. Log Shipping can co-exist with full/differential backups, and with VSS backups, but not Log Backups.

An Availability Group replica is maintained by replicating the log records over the network, not through Log Backups. So that can co-exist with your existing backup strategy.

Answer 2

Log Shipping is taking Log Backups as part of its process, so you don't want another process doing them as well. Just have Commvault pick up those files that the LS_Backup job created.

Standard edition 2017 is limited to one DB for AG...not even sure if you can have an on-prem and cloud for the nodes. If your RPO allows it, for this case Log Shipping is probably the simpler option for pure DR.