About running SQL Server in an active-active clustered environment

Last published : Aug 26, 2026
A SQL Server instance is a completely independent SQL Server installation, with its own services, master database, storage, and memory resources. Each instance is defined uniquely by a separate SQL Server virtual server and service group.
A SQL Server instance can fail over to any of the other nodes configured nodes on its system list.
You can choose an active-active SQL Server configuration where several instances are intended to run on a single node. However, remember that you must configure failover nodes such that a single node can never host more than the number of independent instances allowed by SQL Server.
The following figure illustrates a two node active-active configuration. The SQL Server databases are configured on the shared storage on volumes or LUNs. Each SQL Server virtual server is configured in a separate SQL Server service group. Each service group can fail over to the other node in the cluster.
Figure: Active-active configuration
For example, consider a two-node cluster hosting two SQL Server Virtual Servers, BILLING_VS and PAYROLL_VS.
Table: Active-active configuration
SQL Virtual Server Service Group System List
BILLING_VS BILLING_SG SYSTEM1, SYSTEM2
PAYROLL_VS PAYROLL_SG SYSTEM2, SYSTEM1