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Migarting SQL cluster to SQL high availability RRS feed

  • Question

  • Hi

    Our current SQL server setup runs with 3 X Windows 2016 servers in failover cluster with 2 X SQL instances. All applications refer the SQL by "Instace\SQLSrvrName". Our management asks to migrate all these clustered instances to SQL high availability model because of various including limitation with backup to take clustered hosts. We never configured SQL high availability, looking for an option to migrate the clustered / multiple instance SQL to high availability with minimum downtime. Also it's hard to change the SQL server reference in all apps, so if possible we have to keep the same format even after migrating to SQL HA model.

    Thanks in advance


    LMS

    Monday, September 16, 2019 11:35 AM

All replies

  • What SQL high availability? Log Shipping , Availability Groups ( based on Windows cluster)?

    https://www.sqlshack.com/sql-server-transaction-log-and-high-availability-solutions/


    Best Regards,Uri Dimant SQL Server MVP, http://sqlblog.com/blogs/uri_dimant/

    MS SQL optimization: MS SQL Development and Optimization
    MS SQL Consulting: Large scale of database and data cleansing
    Remote DBA Services: Improves MS SQL Database Performance
    SQL Server Integration Services: Business Intelligence

    Monday, September 16, 2019 11:41 AM
  • Hi LMSU,

    As Uri mentioned, which technology of SQL high availability you want to use?  There are some difference between them. Please refer to Difference Between Always On Failover Cluster, Database Mirroring, Always On Availability Group, Replication and Log Shipping.

    Best regards,
    Cathy 

    MSDN Community Support
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    Tuesday, September 17, 2019 7:14 AM
  • Hi

    Sorry for the delay as we were assigned to a different project. Our intention is to avoid Windows Failover cluster / shared disks completely as our backup solution doesn't support it. 

    We plan to use "Always On Availability Group" as this is the only supported solution. So how can we do the migration from current "Instace\SQLSrvrName" to always on with minimum downtime. Also it's difficult to use a different names with current applications which uses the instance / server names

    Thank You

     


    LMS

    Sunday, October 20, 2019 12:45 PM
  • Hi LMSU,

    just in case remember that for Availability groups a cluster is needed (in case that you want to use automatic failover and listeners... Otherwise you can use clusterless AG without a listener or automatic failover in SQL 2016 and above). If you want minimal downtime you will have to use Log shipping in order to do the synchronization. The cut-over day you will have to change the application/interfaces connection string to use the listener name. 

    hope this helps!

    regards.

    Tuesday, October 22, 2019 1:51 PM
  • >>>We plan to use "Always On Availability Group" as this is the only supported solution. 

    No, using AAG requires Windows Clustering....It looks like  you have to go with LS.


    Best Regards,Uri Dimant SQL Server MVP, http://sqlblog.com/blogs/uri_dimant/

    MS SQL optimization: MS SQL Development and Optimization
    MS SQL Consulting: Large scale of database and data cleansing
    Remote DBA Services: Improves MS SQL Database Performance
    SQL Server Integration Services: Business Intelligence

    Thursday, October 24, 2019 4:46 AM
  • Dear All

    We were trying all options to avoid the migration from Windows Failover Cluster (Always on Failover Clustering) to Always on Availability Group (re-configured the shared disks for the VMs at VMware level by changing the modes RDM / shared vmdk etc to correct issues with backup). 

    Now we decided to go with Always on Availability group. Even if this is based on Windows fail-over cluster, there won't be any shared disk, so this is the only acceptable & working solution in our case.

    So we are looking for multiple options and need your suggestions

    We have 3 instances with existing Failover Clustering (ClusterName1\instance1, ClusterName2\instance2, ClusterName3\instance3) 

    a) What are the options available if we want to keep the same ClusterName\instance and how can we migrate the DBs with this solution

    b) We will create a new name format with Always on Availability group. There are different databases using by different applications (Sharepoint, SCCM etc). We will migrate the DBs for one application at a time to avoid downtime for other applications. How can this be possible

    Thanks in advance


    LMS

    Sunday, December 15, 2019 12:49 PM
  • Any help please?

    LMS

    Tuesday, December 24, 2019 9:02 AM