Microsoft SQL Server Transaction Log Settings

To specify how Veeam Backup & Replication will process transaction logs for VSS-aware applications, switch to the SQL tab of the Processing Settings window and do the following:

• Select Truncate logs to truncate transaction logs of MS SQL and MS Exchange applications after successful backup. The non-persistent runtime components running on the VM guest OS will wait for the backup to complete successfully and then truncate transaction logs. If the job does not manage to back up the VM, the logs will remain untouched on the VM guest OS until the next start of the non-persistent runtime components or persistent components.

• Select Do not truncate logs to preserve transaction logs. When the backup job completes, Veeam Backup & Replication will not truncate transaction logs on the MS SQL or MS Exchange server.

It is recommended that you enable this option for databases that use the Simple recovery model. If you enable this option for databases that use the Full or Bulk-logged recovery model, transaction logs on the VM guest OS may grow large and consume all disk space. In this case, the database administrators must take care of transaction logs themselves.

• Select Backup logs periodically to back up transaction logs with Veeam Backup & Replication. Veeam Backup & Replication will periodically copy transaction logs to the backup repository and store them together with the image-level backup of the Microsoft SQL Server VM. During the backup job session, transaction logs on the VM guest OS will be truncated. For more information, see the Veeam Backup & Replication User Guide, section Microsoft SQL Server Log Backup.

If you choose to back up logs periodically, do the following:

1. In the Backup logs every <N> minutes field, specify the frequency for transaction log backup. By default, transaction logs are backed up every 15 minutes. The maximum log backup interval is 480 minutes.
2. In the Retain log backups section, specify retention policy for transaction logs stored in the backup repository.

• Select Until the corresponding image-level backup is deleted to apply the same retention policy for image-level backups and transaction log backups.
• Select Keep only last <N> days of log backups to keep transaction logs for a specific number of days. By default, transaction logs are kept for 15 days. If you select this option, you must make sure that retention for transaction logs is not greater than retention for the image-level backups. For more information, see Veeam Backup & Replication User Guide, section Retention for Transaction Log Backups.

3. In the Log shipping servers section, click Choose to select what log shipping server you want to use to transport transaction logs:

• Select Automatic selection if you want Veeam Backup & Replication to choose an optimal log shipping server automatically. If the optimal shipping server is busy, Veeam Backup & Replication will direct the data flow to another shipping server so as not to lose data and comply with RPO. The process of transaction logs shipment does not require a dedicated server — Veeam Backup & Replication can use any Microsoft Windows server added to the backup infrastructure.
• To define a log shipping server explicitly, select Use the specified servers only and select check boxes next to servers that you want to use as log shipping servers. The server list includes all Microsoft Windows servers added to the backup infrastructure.

Ensure you select a server that is not engaged in other resource-consuming tasks. For example, you may want not to use a server that performs the WAN accelerator role as a log shipping server. For load balance and high availability purposes, it is recommended that you select at least 2 log shipping servers.

For more information on log shipping servers and how they are selected, see Veeam Backup & Replication User Guide, section Log Shipping Servers.