SQL-Server resource fails to come online with below Error:
[sqsrvres] checkODBCConnectError: sqlstate = 08001; native error = 35; message = [Microsoft][SQL Server Native Client 11.0]A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible.
Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.
Look at the version of (c:\windows\system32\sqsrvres.dll) and install the same version of SQL Server native client.
When Higher version of SQL-Server is installed on a cluster in which lower version of SQL Server is already installed, the lower version SQL Server Resource DLL (c:\windows\system32\sqsrvres.dll) is upgraded to higher version and Higher resource DLL will be loaded by the resource monitor process to monitor Lower version as well.
For example: The Denali SQL Server Resource uses SNAC 11.0 to connect to the SQL instance and because SNAC 11.0 can be used to connect to Shiloh, Yukon and Katmai as well this side by side configuration will work. However if Denali is uninstalled, the Denali SQL Server resource DLL is not downgraded to Katmai, Yukon or Shiloh version and hence care should be taken to not uninstall SNAC 11.0 otherwise Yukon or Shiloh instance cannot be brought online.
Similarly When we install Yukon and Shiloh together, Yukon SQL Server Resource uses SNAC to connect to the SQL instance and because SNAC can be used to connect to Shiloh as well this side by side configuration will work. However if Yukon is uninstalled, the Yukon SQL Server resource DLL is not downgraded to Shiloh version and hence care should be taken to not uninstall SNAC otherwise Shiloh instance cannot be brought online.