sql server clustering x vmware

Question

Hi,

We have a project to migrate from SQL Server 2014 in Cluster to 2019 in Cluster, but the virtualization team doesn't want to use Clustered environments on vmware anymore, they want all SQL Servers in Standalone on vmware, they say the following:

"VMware is already a cluster, and the use of a cluster of virtual machines in the format used by SQL Server requires the use of RAW device disks. This increases the complexity of installing and maintaining resources as the servers are fixed on certain Hypervisors and does not allow the growth of already delivered disks without restarting the entire cluster."

But I say that if the SQL Clustering have a failure of physical hardware, SQL , or Windows host the partner cluster node will take over to minimize your downtime. With virtualization such as VMWare you have high availability at the VMWare (vSphere or ESX) host level, thus if you have vCenter and the host containing SQL goes offline then the SQL Server & its Windows OS will be migrated to another VMWare host. However if the Windows OS or SQL has an issue then the SQL server is offline

Could you tell me if VMware really replaces SQL Cluster, or doesn't it make any sense and why?

Thanks.

Answer 1

Hey,

In both scenarios, in case one of the servers fails, your VM/FCI/AG will failover to the other node. You can go with Availability Groups, which doesn't require RAW disks to build a cluster:
https://learn.microsoft.com/en-us/sql/database-engine/availability-groups/windows/always-on-availability-groups-sql-server?view=sql-server-ver15

You can build FCI avoiding using RAW disks too. StarWind VSAN can be used as a shared storage. The following guide covers the configuration:
https://www.starwindsoftware.com/resource-library/starwind-virtual-san-installing-and-configuring-sql-server-2019-tp-failover-cluster-instance-on-windows-server-2016/

Cheers,

Alex Bykvoskyi

StarWind Software

Note: Posts are provided “AS IS” without warranty of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.

Answer 2

Thanks for the feedback Alex,

But can you tell me in which situations VW would not provide me with high availability like FCI/AG, situations that only FCI/AG would serve me?

I need scenarios for me to tell the VM team that it would not be possible to use only VM as HA, which would need FCI or AG.

Thank you very much.