Configure multiple-subnet Always On Availability Groups and failover cluster instances by modifying CIB
In the Windows world, a Windows Server Failover Cluster (WSFC) natively supports multiple subnets and handles multiple IP addresses via an OR dependency on the IP address. On Linux, there is no OR dependency, but there is a way to achieve a proper multi-subnet natively with Pacemaker, as shown by the following. You cannot do this by simply using the normal Pacemaker command line to modify a resource. You need to modify the cluster information base (CIB). The CIB is an XML file with the Pacemaker configuration. Reference: https://docs.microsoft.com/en-us/sql/linux/sql-server-linux-configure-multiple-subnet?view=sql-server-ver15 Here is an example to create a SQL Server Linux Availability group in 4 nodes in 3 subnets in RHEL 7.6 If you are already familiar with the AG Group setup process, please just jump to step 16. 1.Register your subscription on for all servers (red1,red2,red3 and red4 in this case) subscription-manager register 2.List all available subscription,