windows 2012 server best cpu configuration
- Thread starter rpereyra
- Start date
Hi,
6 cores and 1 socket is you use a singel socket System.
With sockets you emulate a numa architecture and if you have non why emulate it.
If you have 2 sockets and your cpu has more than 6 Core/Threads per Socket use also 6 cores.
6 cores and 1 socket is you use a singel socket System.
With sockets you emulate a numa architecture and if you have non why emulate it.
If you have 2 sockets and your cpu has more than 6 Core/Threads per Socket use also 6 cores.
Thank you.
My server has 2 X E2630v3 CPUs http://ark.intel.com/products/83356/Intel-Xeon-Processor-E5-2630-v3-20M-Cache-2_40-GHz
Is the best config for a Windows VM always nX1?
My server has 2 X E2630v3 CPUs http://ark.intel.com/products/83356/Intel-Xeon-Processor-E5-2630-v3-20M-Cache-2_40-GHz
Is the best config for a Windows VM always nX1?
I personally would set it as an 6 core and 1 Socket or may be 3 core and 2 Socket.
How much Ram has this Host and how much will the VM get?
I mean Host count of DIMMs and GB size per DIMM.
Because this can also be decide what you should set.
If your VM has more RAM then one Socket controls, it would be better to use 2 Socket and 2 cores and activate numa.
How much Ram has this Host and how much will the VM get?
I mean Host count of DIMMs and GB size per DIMM.
Because this can also be decide what you should set.
If your VM has more RAM then one Socket controls, it would be better to use 2 Socket and 2 cores and activate numa.
Thanks Wolfgang. I am interested to learn the logic behind these allocations as we have multiple Proxmox installations each with different configurations. The server I referred to above has 160GB in 10 X 16GB RDIMM. We allocate 32 GB to each Windows Server VM.
KVM are processes in your case 6 with total 32 GB Ram.
The kernel will try (and normaly this work) to keep this 6 thread on one Socket and the 32GB can stay on the RAM of this Socket.
But you should enable NUMA on the VM on this host. Then KVM is aware of this architecture.
It makes more sense to use 2 Sockets, if you have more threads or more RAM then one socket can handle.
The kernel will try (and normaly this work) to keep this 6 thread on one Socket and the 32GB can stay on the RAM of this Socket.
But you should enable NUMA on the VM on this host. Then KVM is aware of this architecture.
It makes more sense to use 2 Sockets, if you have more threads or more RAM then one socket can handle.
Thanks again Wolfgang, I have been reading:
http://www.admin-magazine.com/Archive/2014/20/Best-practices-for-KVM-on-NUMA-servers
Does this all mean that the optional VM CPU configuration is actually dictated by NUMA?
For example: as I have two CPUs each with 16 cores and 160GB RAM then each NUMA node will manage 80GB ram with 1 CPU and 16 cores. If I wished my VM to have more than 80 GB ram or more than 16 cores then I should introduce a 2nd CPU to add another NUMA node?
If this is correct then any VM under 80GB RAM and less than or equal to 16 cores only needs a single CPU.
Presently I have 3 Windows VMs with 32GB each setup as 2X4, 4X4 & 2X4. I have attached a screenshot of the numactl -H & numastat, I see a lot of misses. Over the weekend I will reconfigure the VMs to be 1X8, 1X16 & 1X8 and see what difference that makes to numastat.
Having said all this I am unsure of how enabling NUMA with only a single CPU makes any difference?
http://www.admin-magazine.com/Archive/2014/20/Best-practices-for-KVM-on-NUMA-servers
Does this all mean that the optional VM CPU configuration is actually dictated by NUMA?
For example: as I have two CPUs each with 16 cores and 160GB RAM then each NUMA node will manage 80GB ram with 1 CPU and 16 cores. If I wished my VM to have more than 80 GB ram or more than 16 cores then I should introduce a 2nd CPU to add another NUMA node?
If this is correct then any VM under 80GB RAM and less than or equal to 16 cores only needs a single CPU.
Presently I have 3 Windows VMs with 32GB each setup as 2X4, 4X4 & 2X4. I have attached a screenshot of the numactl -H & numastat, I see a lot of misses. Over the weekend I will reconfigure the VMs to be 1X8, 1X16 & 1X8 and see what difference that makes to numastat.
Having said all this I am unsure of how enabling NUMA with only a single CPU makes any difference?
