We currently have an old SQL Cluster (just 2 modes) on physical servers, which we will be moving to a VMware Cluster infrastructure. My question, since the VMware is already clustered, does it make sense to cluster the SQL again?
Yes. I'm guessing you want the ability to keep the SQL cluster up while performing updates and such on individual VMs. Or in case one goes down/gets corrupted/etc. Basically all the reasons you presently are running as a cluster.
You can also set up affinity rules (depending on VMware subscription level?) to force the SQL server instances to run on separate hosts. So if one host goes down you still have an instance running on another.
Yes, VMware wont provide application redundancy...so you still need to setup the cluster/AlwaysOn.
Also, while I know you can technically virtualize MS SQL, I would exercise caution and analyze your current I/O performance and compare it to what you will get in the VMware cluster. SANS wont match the performance of direct attached SAS drives which could be a critical factor in DB performance.
Many thanks for your answers. The cluster types would include the standard SQL Cluster and also AlwaysOn, no mirroring.
I am also afraid of the performance but this push is over my pay grade. I have already included that in my risk assessment to this idea/plan. It gets worse because this service provider we are going to, we actually have no clue how their infrastructure is setup and configured. I preferred actual physical machines when it comes to SQL...
I've recently moved the physical SQL cluster into VMware cluster. The main task was to use FCI approach in the VMware. We have decided to rework storage architecture also and move from old SAN box into something new. Since we need iSCSI storage to be able to create SQL cluster, we have tried different SDS solutions (datacore, starwind, hpe storevirtual) and decided to use starwind vsan free (quite simple to set up and allows to create 2 node storage replication in active-active manner - https://www.starwindsoftware.com/starwind-virtual-san) for iSCSI HA storage sharing. I've pretty much the same setup besides the SDS software is now in charge instead of classic SAN storage.