Hi all, I’m a bit confused about number of vCPU that should be assigned to FSVM. For example, I have 4 nodes and each node with 2 sockets (i.e. 2 vCPU) and each with 16 cores (i.e. total 32 cores per node). When creating FSVM, for example, each FSVM needs 8 vCPUs, but I have 2 vCPUs per node only. And we need at least 3 FSVM, that means we need 24 vCPUs. Is that mean I must have at least 12 nodes? And each vCPU with 1 core only?
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Userlevel 6
+8
No. You have 32 (Lets call them pCPU) cores and with hyperthreading enabled 64 threads.
vCPU is the cpu assigned to virtual machines.
Offcourse the number of vCPU is not bound to the available pCPU.
We overcommit vCPU against pCPU.
Userlevel 3
+7
there is something call oversubscription , as jeroen mention dont confus yourself with physical core vs vCPU.
in your case dont woory about physical core just go ahead create FSVM with 8 core.
AHV lets you configure vCPUs (equivalent to CPU sockets) and cores per vCPU (equivalent to CPU cores) for each VM. Nutanix recommends first increasing the number of vCPUs when a VM needs more than 1 CPU, rather than increasing the cores per vCPU. For example, if a guest VM requires 4 CPU, Nutanix recommends using 4 vCPU with one core per vCPU.
Thanks for all the information. Seems I misunderstood the word “equivalent”. I thought it means “number of CPU socket = number of vCPU”. Clearly it’s incorrect.
So in my example, how many vCPU are there per node if oversubscription is not used?
Userlevel 6
+8
32, But that means you do a 1:1 mapping. I always count with 1:6 for generic server workloads.
Userlevel 3
+7
for database related or mission cretical vms i do 1:1 or 1:2 for other work load i do 1:4 or 1:6
Thanks everyone for the advise!
For Nutanix Files it depends on the connections and workload your Nutanix Files is used for:
Check the “Nutanix Files Sizing Guide”
https://portal.nutanix.com/page/documents/solutions/details?targetId=TN-2066-Nutanix-Files-Sizing-Guide:share-design.html
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