Skip to main content

Questions tagged [numa]

Non-Uniform Memory Access is what it stands for. For x86 architectures this is the method used to handle memory architectures where each processor has local memory and accessing another processor's memory is appreciably more expensive.

Filter by
Sorted by
Tagged with
0 votes
1 answer
94 views

How Linux processes and modules choose numa node

I have a Ubuntu 22.04 server which is numa enabled node with 4 nodes. Comparatively other nodes, memory usage is high on node0. I noticed this contains most of the system binaries, services and ...
Rama's user avatar
  • 87
0 votes
0 answers
14 views

Numa different allocations

We have a physical server with Ubuntu 22.04 OS. The default numa policy is 'local'. As far as I know, 'local' policy should stick only one numa node. In this scenario, memory being mapped across all ...
Rama's user avatar
  • 87
0 votes
0 answers
27 views

Ubuntu NUMA memory policy

So far I was known that there are two types of NUMA memory policies which are "per task/process" and "Per memory region". As per below numa_map entry, I have few queries. Can you ...
Rama's user avatar
  • 87
3 votes
0 answers
129 views

NUMA CPU affinity issue

I have a Ubuntu server with 22.04 OS. I encountered an issue with NUMA affinity bound. 1.) Server has two NUMA nodes accordingly. server-1:# numactl -H available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 ...
Rama's user avatar
  • 87
0 votes
0 answers
152 views

Optimizing CPU and Memory use on Multi-socket NUMA server

I am building a server that will be used by interns in my company to connect to and perform some tasks. The server is running AlmaLinux 9 and using KVM to run Windows 11 guests. The server has 2 CPU ...
Fabz's user avatar
  • 1
1 vote
2 answers
311 views

NPS4 on a Threadripper 3960x gives two nodes with no memory at all

I set my 3960x to NPS4 (Nodes Per Socket: 4) mode to experiment with NUMA on Linux. My system has 4 32 GiB DIMMs across 4 channels, so I expected each of the 4 nodes to get one. Instead, nodes 1 &...
Tavian Barnes's user avatar
1 vote
1 answer
869 views

Should I worry about "Unknown NUMA node; performance will be reduced"?

I have a NUMA system with two Xeon E5-2680 v3's. System is running Debian 11.5 (Proxmox VE 7.3-3). When making sure that NUMA was enabled I noticed this in my dmesg: root@(host):~# dmesg | grep -i ...
Kaiden Prince's user avatar
0 votes
1 answer
230 views

Use of dual-port NIC

I was wondering, what is the purpose of a dual-port NIC on a blade compute unit, in the context of a datacenter rack, like which of these configurations is more in line with modern datacenter ...
Mihir Shah's user avatar
0 votes
1 answer
245 views

Uneven cpu utilization linux dual socket server

Recently I noticed on two of our servers strange distribution of tasks. Both servers are dual cpu EPYC 7402 physically the same platforms, running the same tasks, differ in numa configuration, kernel ...
Mardaker's user avatar
2 votes
1 answer
1k views

Recommended NUMA nodes per socket on dual AMD Epyc 7643 server with 1TB of RAM

What do you suggest to set the NUMA nodes per socket to? It is factory set to NPS1, but I'm not sure if this is the most optimal value. (We use this device for massively multithreaded bioinformatic ...
Balázs Horváth's user avatar
0 votes
1 answer
874 views

How to calculate the QuickPath Interconnect (QPI) bandwidth?

For Xeon E5-2697 v2, Intel lists: Bus Speed = 8 GT/s # of QPI Links = 2 According to Wikipedia, one must know the QPI frequency and link width to calculate the QPI bandwidth, but these don't seem to ...
MWB's user avatar
  • 187
1 vote
1 answer
275 views

Incorrect # of Hugepages in `numstat`

I asked a similar question years ago. Now, my machine has four 1G hugepages and 256 2MB hugepages: # cat /sys/devices/system/node/node0/hugepages/hugepages-1048576kB/nr_hugepages 4 # cat /sys/devices/...
HCSF's user avatar
  • 255
1 vote
1 answer
929 views

Latency of memory accesses via interconnectors

I'm trying to compare latencies of different node interconnects for a cluster. The goal is to minimize the memory access latency. I have obtained some benchmarks regarding one of the hardware ...
Piotr M's user avatar
  • 33
2 votes
0 answers
426 views

Current single system image solutions

I'm designing a cluster for a small research institute. Since our computations require a large amount of memory, I'm looking for a solution that will allow our applications access to the whole memory ...
Piotr M's user avatar
  • 33
2 votes
0 answers
722 views

VMware Cross-NUMA Performance penalty

I've been experiencing random unexpected slow-downs of a virtual SQL Server that I can't attribute to workload, storage or CPU (in fact it continued after the host was evacuated of other VMs). I ...
Peter Godwin's user avatar
2 votes
1 answer
916 views

DELL PowerEdge R740xd - NUMA - memory performance

I have two physical database servers (both Windows Server 2016): test server (5 years old): DELL PowerEdge R730xd, 1x Intel(R) Xeon(R) CPU E5-2637 v4 @ 3.50GHz (4C/8T), 192 GB RAM (12x 16GB PC4-...
teo's user avatar
  • 143
3 votes
0 answers
756 views

Consecutive CPU numbering on multi-socket NUMA Linux system

I've noticed that CPUs are numbered by Linux according to quite different schemes on different multi-socket NUMA systems. I mean the CPU numbers you use in kernel parameters such as isolcpus= or when ...
maxschlepzig's user avatar
  • 1,035
0 votes
1 answer
2k views

how libvirt cputune config goes to qemu-kvm

I am porting xml libvirt config to qemu executable arguments. Simply I have .xml vm config from virsh edit vm-name and I want to run the same vm machine by executing qemu-system-x86_64 with special ...
Andrey's user avatar
  • 3
0 votes
1 answer
703 views

NUMA 1 not used on SQL Server 2008 R2 on Windows Server 2008 R2 on ESXi

We've got Microsoft SQL Server 2008 R2 running on Windows Server 2008 R2, virtualized on VMWare ESXi 6.7.0. The server has 2 CPU sockets with 22 cores each. The VM is allocated 8 sockets with 3 cores ...
tilkov's user avatar
  • 263
0 votes
1 answer
327 views

Incorrect # of Free Hugepages in `numastat`

$ numastat -vm Per-node system memory usage (in MBs): Node 0 Total --------------- --------------- MemTotal 32464.24 32464....
HCSF's user avatar
  • 255
1 vote
1 answer
1k views

Virtualbox performance on NUMA host (AMD Epyc)

At a small software development house, we virtualize our build servers (using VirtualBox) so that they can be easily backed up, snapshotted and the like. We've recently bought a new server using an ...
Atomjack's user avatar
2 votes
0 answers
40 views

Slurm - Does it maintain ccNUMA?

Does a SLURM cluster control, maintain or enforce Cache Coherence across the Nodes? Is it a configuration property, or does something like this not exist? I can't find anything inside the docs.
Semo's user avatar
  • 271
1 vote
0 answers
400 views

Linux NFS server NUMA affinity - pool_mode

From the Linux kernel-parameters.txt I have seen that it is possible to change the NFS pool behaviour to have the nfsd threads bound to NUMA zones. The parameter in question is sunrpc.pool_mode and ...
Thomas's user avatar
  • 4,305
1 vote
0 answers
607 views

openstack shared PCI between numa with SR-IOV

I'm building SR-IOV supported compute node on HP 360g8 hardware and i have Qlogic interface card, my compute node has 32 core & 32GB memory. Problem: when i launch vm-1 (with flavor 16 vCPU core)...
Satish's user avatar
  • 672
2 votes
0 answers
232 views

Bad performance on better hardware

I have postgresql streaming replication on 2 hosts and I've faced with the problem of different performance compared between two servers. It looks like all sql queries on one host are slower on 70-90% ...
lesovsky's user avatar
  • 243
1 vote
0 answers
2k views

Memcpy bandwidth ~1.6x faster on 1 vs 2 socket Intel Scalable (Skylake)?

I'm in the process of porting a complex performance oriented application to run on a new dual socket machine. I encountered some performance anomalies while doing so and, after much experimentation, ...
Dave's user avatar
  • 121
36 votes
1 answer
4k views

Unexpected and unexplained slow (and unusual) memory performance with Xeon Skylake SMP

We've been testing a server using 2x Xeon Gold 6154 CPUs with a Supermicro X11DPH-I motherboard, and 96GB RAM, and found some very strange performance issues surrounding memory when compared to ...
Marc Micalizzi's user avatar
4 votes
0 answers
373 views

Hyper-V 2016 DDA issue: a VM boot fails when a drive is connected to an opposite NUMA node

Brief description: the host is Windows Server 2016 Datacenter Build 14393 (UEFI) running Hyper-V role. SR-IOV and Intel VT are enabled. 4x Intel® Optane ™ SSD 900P 280GB PCIe NVMe 3.0 drives are ...
Mr. Raspberry's user avatar
0 votes
4 answers
9k views

Hyper-V: Not enough memory to start VM although there are plenty left

I'm having this error on my server: "Not enough memory in the system to start the virtual machine. Ran out of memory (0x8007000E)" when starting an 8 GB VMs on a 12 GB RAM FREE server. Here is my set ...
Hiền Phạm's user avatar
0 votes
1 answer
5k views

Does disabling "numa interleave" from bios cause memory page-out(when cpu-1 has no free memory left) to hdd on all dual-cpu systems?

For an example system of a dell dual 4114 silver with 24GB per CPU; how would it work if my application allocates 24 GB at once? Should I be concerned about write-life of my SSD because of pagefile ...
huseyin tugrul buyukisik's user avatar
7 votes
2 answers
10k views

NUMA CPU numbering in Linux

I have access to two NUMA servers. One of them is Dell R720 and has these CPUs: $ cat /proc/cpuinfo |grep Xeon|sort|uniq -c 24 model name : Intel(R) Xeon(R) CPU E5-2630L v2 @ 2.40GHz The other ...
juhist's user avatar
  • 322
5 votes
1 answer
480 views

Server computational slowdown when RAM is used extensively

I have problem with server slowdowns in very specific scenario. The facts are: 1) I use computational application WRF (Weather Research and Forecast) 2) I use Dual Xeon E5-2620 v3 with 128GB RAM (...
Ivan Toman's user avatar
1 vote
1 answer
71 views

Opteron 6274 Cache Differs from Manufacturer's Specs in Windows Server 2016

I just upgraded a DL585 g7 server by replacing its Opteron 6172 CPUs with 4 Opteron 6274 CPUs. Every source I read says that the Opteron 6274s are supposed to have 8x2MB of L2 Cache and 16MB of L3 ...
C.P.'s user avatar
  • 11
2 votes
2 answers
2k views

NUMA placement failed, performance might be affected

I'm running SuperMicro 6048R-E1CR36H Storageserver on Ubuntu Xenial 16.04.03 LTS and Xen Kernel: 4.4.0-97-generic Xen: xen-hypervisor-4.6-amd64:amd64/xenial-security 4.6.5-0ubuntu1.2 Problem: when ...
PHZ.fi-Pharazon's user avatar
0 votes
1 answer
3k views

Ryzen Threadripper CPU does not report multiple NUMA nodes [closed]

Just booted Arch Linux on a Ryzen Threadripper 1950X server that I built and use in my company. Please don't close this question. It is relevant for anyone using Linux on Threadripper and running NUMA-...
Aleksandr Dubinsky's user avatar
0 votes
1 answer
3k views

Change the NUMA node where a PCIe device is attached

Modern servers using multiple physical CPU sockets have NUMA. PCIe devices are attached to one specific NUMA node as the PCIe controller is embedded in the physical CPU chip. Is it possible to change ...
Mircea Vutcovici's user avatar
3 votes
1 answer
2k views

Is a machine with a single NUMA node, actually a regular (non-NUMA) system?

First, let's check I got the fundamentals right: As I understand it, NUMA systems are a (asymmetric) network of NUMA nodes, where a NUMA node is usually (but not always) a physical CPU package. In a ...
Edd Barrett's user avatar
2 votes
0 answers
113 views

find out NUMA locality of process RAM

I am doing an application benchmark with multiple instances of the same application. I found out that pinning their processes (with sched_setaffinity under Linux, with TaskManager under Windows) to ...
Thorsten Staerk's user avatar
1 vote
1 answer
1k views

ZFS on Linux and KVM: NUMA nodes for host

I am interested in using KVM images on zvols under ZFS on Linux, on a multi-socket system. I am wondering how I should pin NUMA nodes so as to maximize the benefits of ZFS ARC cache for all KVM images ...
Stonecraft's user avatar
2 votes
1 answer
1k views

NUMA node interleaving doesn't work for MariaDB

Please help activating NUMA node interleaving for MariaDB. Using MariaDB 10.1.21 on CentOS Linux release 7.3.1611. Per instructions on https://mariadb.com/kb/en/mariadb/systemd/ added /etc/systemd/...
ivp's user avatar
  • 33
0 votes
0 answers
371 views

CPU & Memory Reservation in vSphere & Numa concept

by googling/studying vSphere documentation I have found the possibility to use "Reservation" concept in vSphere. What it is not clear to me is : CPU and Memory reservations are configured separately ...
Prisco's user avatar
  • 101
1 vote
0 answers
141 views

Writing a Numa load balancer

I originally asked this question on StackOverflow, but as there came no answers, and this question is more about how to configure a server, this question might be more suited on ServerFault. I have ...
Patrick's user avatar
  • 227
0 votes
1 answer
365 views

What is NUMA node limit in modern Windows OS

What is the highest number of NUMA nodes in Windows 10 / Server 2012? In Windows 7, it was documented that OS supports only up to 4 NUMA nodes1 but with modern systems supporting 320 logical ...
gabr's user avatar
  • 363
2 votes
2 answers
241 views

Is NUMA always completely NUMA or are there also hybrid systems?

I am working on a high-end server application where performance is critical. Given that servers are often employ NUMA-architectures, the server application also uses NUMA-aware memory allocation ...
Patrick's user avatar
  • 227
-1 votes
2 answers
2k views

Hyper-V NUMA setting

My machine is running on Window 2012 R2, with 48 Logical processors and 240GB RAM. I have create a VM with 48 processors and 230GB ram. I am double about the NUMA nodes I should create and memory ...
Louis Lee's user avatar
9 votes
1 answer
763 views

How would I know if I should be disabling virtual NUMA on VMs running older applications?

From VMware's docs: Virtual NUMA topology is available to hardware version 8 virtual machines and is enabled by default when the number of virtual CPUs is greater than eight. You can also ...
red888's user avatar
  • 4,273
6 votes
1 answer
2k views

DL380 Gen9 which processor and what impact on NUMA

We are about to build a new server and I was wondering what would the impact on NUMA with the options available. The system will be built using a Proliant DL380 Gen9 8SFF which has 2 sockets, and 12 ...
Tom V's user avatar
  • 177
0 votes
1 answer
353 views

HyperV memory per NUMA node

I have some issue with memory allocation on my Hyper-V 2012 R2 server. Server has 16GB of RAM, with 2 x 12 core CPUs. When I run Get-VMHostNumaNode, I am getting following results: NodeId ...
Ivan ho ho ho's user avatar
0 votes
1 answer
103 views

NUMA processor definition

NUMA, non-uniform memory access designates a symetric multi-processing system where processors are grouped into nodes, with each group sharing some level of memory, so that memory access on same node ...
kiriloff's user avatar
  • 129
3 votes
0 answers
1k views

Kernel parameter isolcpus seems to have no effect on Ubuntu Server with NUMA

I use the isolcpus kernel parameter to restrict the CPUs the Linux scheduler should use to place processes. cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-4.2.0-18-generic.efi.signed root=UUID=78e5b46f-...
jgjl's user avatar
  • 31