Mixing v3 and v4 processors in a cluster

[andyarnet]

Looking for some advice on this.  We currently have two vSAN clusters, all hosts with E5-2630v3 processors, one hybrid, one all-flash, EVC enabled on both clusters.  We were planning to change the hybrid hosts to all-flash and move them into the all-flash cluster, creating one large cluster, and add a new host at the same time.  Problem is, our hardware vendor is telling us that the v3 processor is no longer available and is proposing the v4 processor.  So now I am rethinking what we're doing.

Cluster1 (Hybrid) - 4 hosts:

     E5-2630v3 x 2

     256GB RAM

     2 x 400GB Intel P3700

     8 x 1.2TB 10K SAS

Cluster2 (All-Flash) - 5 hosts

     E5-2630v3 x 2

     256GB RAM

     2 x 400GB Intel P3700

     4 x 1.92TB SSD

The plan is to replace the 10K drives in the hybrid hosts with SSDs and move them into them into the all-flash cluster.  And add an additional host in the process.  So ultimately a single 10-host all-flash cluster.

So here are my questions:

1.     Is it ok to have 9 hosts with v3's and 1 with v4's in the same cluster?

2.     How will DRS handle VM placement, given that one host will have 20 cores while the others have 16 cores?

3.     Should I look into upgrading the processors on all the hosts?

I know that ideally with vSAN all the hosts are identical configs.  The storage config will be the same, just one host will have more (slower) cores.

Any suggestions?

Thanks,

Andy

[krobertsIAA · Accepted solution]

1. I can attest to #1 being ok, we are at haswell levels of evc now, no issues.

2. DRS will balance based on performance and you (p:v) ratios.

3. I wouldn't say you HAVE to buy all new cpus. That is what EVC is for, to create a common baseline. Just keep circulating hosts and keep up to date with ESXi versions to get those new baselines.