Service Pack and Cumulative update in SQL Server Failover Cluster

Question

Hi,

We have 2 node SQL Server Failover cluster of 2012, 2014, 2016 & 2017 versions. We need to apply service pack and cumulative update. Is it possible to apply service pack/cumulative update one node at a time and keep SQL server service on to remaining nodes to minimize the downtime?

Regards
Arif

Answer 1

Hi @Kazi Ariful Haq ,

Yes you can, you should perform the updates in a similar fashion as mentioned below:

1. Backup all databases.
2. Failover all SQL cluster roles to Node A.
3. Install the patches on Node B (passive).
4. Restart Node B.
5. Failover all SQL cluster roles to Node B.
6. Install the patches on Node A (passive).
7. Restart Node A.

You may also follow the official documentation over here:

Upgrade a failover cluster instance
https://learn.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/upgrade-a-sql-server-failover-cluster-instance?view=sql-server-ver15

----------

(If the reply was helpful please don't forget to upvote or accept as answer, thank you)

Best regards,
Leon

Answer 2

Please see:

https://learn.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/upgrade-a-sql-server-failover-cluster-instance?view=sql-server-ver15#perform-a-rolling-upgrade-or-update

This applies to version upgrades, service packs, and cumulative updates.

Answer 3

Hi @Kazi Ariful Haq ,

Also refer to the following posts for the basic steps.
https://sqlha.com/2011/05/10/patching-clustered-sql-server-instances-with-sql-server-2008-and-sql-server-2008-r2/
https://dba.stackexchange.com/questions/133595/installing-a-sql-server-patch-on-a-node-within-a-2-node-fci

---

If the answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 4

One good question will be if the way for SQL Failover cluster and the way for SQL Always On is the same (for example MS SQL 2016 SP3).
Because in opposite to SQL Always On will the SQL Failover Cluster have the SQL part (Binaries) as shared resources. The SQL Always On always have the SQL Binaries local and only the HA DB will run inside the cluster or better a pointer to the local resources (DB).

In other words: SQL failover cluster (the classic one), is it possible to implement a SP (to the inactive on) if the resources are owned by the other node. The Always On have primary and secondary roles, there the way is clear, because primary and secondary will act also as a local MS SQL installation and you patch the local part and the HA DB together (First the secondary than the primary).