Memory and cores allocation to VM

[pranit]

Hello team,
If my host server on which proxmox is running has 64 GB of RAM and 22 cores each on two sockets which means 44 Max vCpu can be used so if I want to create VM and give him a maximum cores and Ram that is 64 GB of RAM and 44 cores to one particular VM inside proxmox can this be possible ? does proxmox requires some fixed cores and some amount of Ram to function.
Pls guide.

 

[Dunuin]

PVE needs some free cores (1 or 2 should be fine), because if all guests bring the physical CPUs to 100% utilization there would be no CPU time left for PVE itself, so it couldn't hypervise the guests. And you want atleast 2GB RAM for PVE itself.
Also keep in mind that KVM will have overhead, so if you assign 64GB RAM to a VM the KVM process virtualizing the VM will use more then 64GB of the hosts RAM. And you want some free RAM on your host for caching. Especially if you use ZFS, ZFS wants alot of RAM for caching too. By default ZFS will use up to 50% of your hosts total RAM, so up to 32GB in your case in case you don't manually limit that.

Don't try to overprovision the RAM, that wont work.

Why do you want virtualization at all if you just plan to run a single VM giving it all the ressources?

 

[pranit]

PVE needs some free cores (1 or 2 should be fine), because if all guests bring the physical CPUs to 100% utilization there would be no CPU time left for PVE itself, so it couldn't hypervise the guests. And you want atleast 2GB RAM for PVE itself.
Also keep in mind that KVM will have overhead, so if you assign 64GB RAM to a VM the KVM process virtualizing the VM will use more then 64GB of the hosts RAM. And you want some free RAM on your host for caching. Especially if you use ZFS, ZFS wants alot of RAM for caching too. By default ZFS will use up to 50% of your hosts total RAM, so up to 32GB in your case in case you don't manually limit that.

Don't try to overprovision the RAM, that wont work.

Why do you want virtualization at all if you just plan to run a single VM giving it all the ressources?

Thank you for your response..

The reason being I have to use only one VM in proxmox, is that I can utilise maximum vcpus from it. My current standalone application on a physical server requires more cores than it actually has. Physical server has to total 16 cores comprising two sockets. Application requires at least 30 cores so this is the reason I am planning to migrate my this application server on proxmox having 16 gb of ram and 16 core (8+8) 2-sockets so that I can use this single VM to obtain maximum cores. By doing this can I get maximum or improved processing performance for my application? Can anyone lights on this. Thanks in advance.

 

[pranit]

Need some suggestions on above pls.