"True, but you can have an all-flash pool and then a hybrid that has flash for caching and spinning disk for the bulk of the storage. As is mentioned in the question, there is 1 all-flash and 2-hybrid pools."
No, vSAN OSA does not use "pools", you are maybe confusing how this might be configured in SANs e.g. have a group of SSDs or a group of HDDs and leverage these as individual entities for specific purposes.
@pcgeek2009 In vSAN OSA each node can have Disk-Groups comprised of either 1x Cache-tier SSD/NVMe + 1-7x Capacity-tier SSD/NVMe/HDD.
However, for many good reasons, it is not supported to have some Disk-Groups with Capacity-tier being HDDs and others as SSDs.
"I have 3 disk groups per server in my vSAN cluster 1 All Flash and 2 hybrid, I'm just wondering if I can define a tag or policy for some VMs to only use all-flash diskgroups and not hybrid disk groups?"
@miladmeh8 Milad, if this is some test cluster you are using or your own home-lab, then sure it is technically feasible to place data on just the AF disks (though as FTT=0 and thus no redundancy) using a affinity rule pinning the data to just that one node (or DG), if this is anything other than a homelab then don't do this.
