For each SQL Server VM guest OS, Veeam Backup & Replication defines the way it will transport log backup files to the backup repository. Two transport types are supported:
- Direct data transfer between the VM guest OS and repository. This is a recommended method as it does not involve additional resources and puts less load on the VM guest OS.
- Alternatively, if it is not possible to establish direct connection, you can configure Veeam Backup & Replication to use a Microsoft Windows host added to the backup Infrastructure as a log shipping server. You can select server(s) from the list, or instruct Veeam Backup & Replication to automatically choose an optimal log shipping server from the Managed Servers (that is, added to backup infrastructure in Veeam backup console). The choice will be based on two criteria: possible data transfer method(s) and network availability.
Possible data transfer methods for log shipping server are:
- Network – this is a default method which can be used for both platforms. It uses the VM guest OS to obtain files and then transfer them over the network. To offload the VM guest OS, logs are created one by one (not simultaneously); 1 log creation request is created for every DB.
- VIX - this method can be used for VMware VMs only. It allows you to obtain guest files bypassing the network. In this case, for each SQL instance, 1 log creation request is created for all DBs (grouped by instance).
Network availability criteria are based on the location of the Microsoft Windows host and VM guest OS. Otherwise, Veeam Backup & Replication detects if any of the following is applicable to the Microsoft Windows host:
- Microsoft Windows host is located on the same ESX(i) host as the VM guest OS.
- Microsoft Windows host and the VM guest OS are in the same sub-network
- Microsoft Windows host and the VM guest OS are in different sub-networks (the production infrastructure is isolated from the backup infrastructure).
So, when choosing as log shipping server for log transfer, top priority goes to the Windows host “A” that supports the Network data transfer mode.
You may not want some of your busy managed hosts to participate in the process – if so, use manual server selection when assigning the role of log shipping servers. It is also recommended that you have not only one dedicated Windows host for log shipment, but also a redundant host for availability purposes.
Veeam Backup & Replication automatically re-detect available hosts, so if a log shipping server fails for some reason, processing will be performed by another server.