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Is it possible to have async in a KVM with only one vCPU core?

I'm running a cheap VPS plan with only 1 vCPU core. My webapp's backend has asynchronous operations using python concurrent.futures. It works fine on my machine, but in the VPS, the async operation ...
No Name's user avatar
  • 101
3 votes
0 answers
85 views

Spread IPsec decryption over multiple CPUs

All IPsec traffic being decrypted is processed on a single CPU, despite having multiple IPsec tunnels (SAs.) How can I get the load shared across multiple CPUs? I'm running Strongswan IPsec on Ubuntu ...
Jeff Learman's user avatar
0 votes
1 answer
254 views

What is the correct KVM VM vCPU config in cockpit for proper load balance on physical CPUs

I have dual CPU server. I want to run some VMs on top of it. While configuring VMs thru cockpit (on redhat 8.0). I cam across this screen: I just want to allocate 8 cores with 4 on each physical CPU. ...
rajeev's user avatar
  • 101
0 votes
1 answer
50 views

Exploring Advanced CPU Virtualization: Amalgamating Cores for Enhanced Performance [duplicate]

Virtualization experts! I have a question that revolves around a potential CPU virtualization concept illustrated below. Is there an existing implementation of this idea, or are there hardware ...
pmaniyan's user avatar
  • 101
6 votes
2 answers
5k views

How do physical multi-core CPUs relate to vCPUs

I've been told that the third-party application I need to host on a Windows Server 2022 box needs 3 CPUs with 8 cores but my enterprise cloud provision service (it's in-house at work) specifies ...
endurium's user avatar
  • 163
0 votes
0 answers
125 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
2 votes
1 answer
3k views

QEMU SMP options

I'm trying to understand the QEMU smp option. Currently I have set it to: smp 4 As far as I understand that should create 4 vCPU (with 1 core and 1 thread I suppose). Would it be better for ...
Maestro's user avatar
  • 325
2 votes
1 answer
2k views

Dynamic CPU allocation/scaling in QEMU KVM

How can I dynamically allocate/scale CPU resources to my QEMU VM according to the workload of the VM? Would this require a script? Is it even possible to change CPU allocation at runtime? I have a ...
Anm's user avatar
  • 203
0 votes
1 answer
762 views

How to configure Openstack so that it considers that 32 vcpu is available instead of 16vCPU?

OpenStack Xena CentOS 8 Stream My task is to increase from 16 vCPU to 32 vCPU. I'm trying to overcommit, but it doesn't work. I have one controller and one compute. Compute output: [root@controller ~(...
Maksim's user avatar
  • 113
1 vote
1 answer
343 views

vcpu counts aren't changing after config change and reboot

I recently downsized the number of vcpus virtual server Echobox1 uses from 4 to 1. before: # virsh vcpucount Echobox1 maximum config 4 maximum live 4 current config ...
a coder's user avatar
  • 809
2 votes
1 answer
2k views

Set CPU affinity for specific VM on vmware ESXI using govc CLI

I have shell scripts that I use to programmatically configure my Virtual Machines (VMs) on my vmware ESXi host. I use the "govc" command-line-interface (CLI) which provides a suite of ...
XxaemaethxX's user avatar
-1 votes
1 answer
273 views

KVM with 1 vCPU has CPU load above 1

I have a KVM running with 1 vCPU on a machine with 4 cores. lscpu in the KVM gives me 1 CPU with 1 core : Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte ...
Mathieu Rollet's user avatar
-5 votes
1 answer
128 views

Google compute - Less vCPUs high IOPS vs More vCPUs low IOPS [closed]

My Postgresql databases are running on Google compute instances N1 with custom(26 vCPUs, 52 GB memmory) with a pessistent ssd disk 1.2TB . This setup is way underused, but keep the Read IOPS under 3k. ...
Denis Argentin's user avatar
0 votes
1 answer
446 views

How to load one physical CPU in a system with virtual cores?

I have an AMD processor with 4 physical cores and SMT enabled. Because of the latter, I see 8 virtual cores in a Linux box. For example, stress command can spawn a number of workers spinning on sqrt()....
mate200's user avatar
3 votes
2 answers
6k views

Azure VM Core vs vCPU

When comparing two different VM series in Azure, I see that one has Cores and the other one vCPUs. Keeping aside the number of Cores/CPUs, Memory and Processor Type (Intel Xeon E/Platinum etc), what ...
Thomas's user avatar
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9 votes
1 answer
3k views

Do CPU credits exist for c5d.large instances? And if not, why not?

I've been paranoid that the websocket feed I was listening to on a t3.micro instance was being inhibited by cpu steal time from other instances under the same hypervisor. So I switched over to a c5d....
randy's user avatar
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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
2 votes
1 answer
4k views

How to identify CPU(s) on Linux EC2 instance?

I'm running a Linux c5d.9xlarge instance and wondering what CPU it's using. Amazon's Instance Types webpage states: C5 and C5d 12xlarge, 24xlarge, and metal instances have the following specs: ...
apptree's user avatar
  • 365
0 votes
1 answer
248 views

Google Cloud Configuration CPUs

I need to configure a machine on Google Cloud Platform (Brazil/Sao Paulo) to run a biometric service and my software provider requested a machine with the following specification: "2 x Intel® ...
Rafael's user avatar
  • 3
0 votes
1 answer
273 views

libvirt hot unplug cpu

I'm currently working with libvirt. after i reduce the number of vcpu cores with below command, the operation will be completed successfully. i should also mention that my current and max vcpus is 4, ...
nima's user avatar
  • 3
1 vote
0 answers
371 views

processor type differences between elasticache instance types , will all instances suffer the same way?

This may sound like yet another, "what is a vcpu" or "should I use elasticache, remember its single threaded!!" question --- but I think this asks a question unanswered. redis is single threaded, ...
Muradin007's user avatar
8 votes
4 answers
15k views

How does the vCPU align with the CPU? (VM with more cores than the CPU has)

I have a VM running on vSphere 6.5.which has 24 vCPU's. The server has two physical cpu's (xeon e5-2699 v4) which have 22 cores and hyperthreading is enabled. How exactly are the vcpu's running on ...
user3235860's user avatar
0 votes
1 answer
2k views

aws ec2 t2.small vs t2.medium CPU performance

Since t2.medium has 2 VCPU and t2.small has 1 VCPU would it be faster as a web server? (Apache/php). I am wondering if I upgrade if I will gain any performance benefits.
Chris Muench's user avatar
2 votes
0 answers
97 views

Will More vCPU's and RAM Help Protect Against Some Smaller Scale DDoS Attacks?

Obviously having more vCPU's (virtual CPU's) and more RAM by them self won't be able to alone help stop and/or prevent a DDoS attack, but let's say after a DDoS attack is finished and/or slowing down ...
rflxdev's user avatar
  • 21
1 vote
0 answers
154 views

Performance on Pinned CPU cores versus automatically managed?

I have a XenServer 7.5 environment where I'm running a single Windows VM with 16 total vCPU's. My server has dual Xeon E5-2620v4 CPU's with 8cores/16threads each clocked at 2.1GHz nominal and a Max ...
Felix Jen's user avatar
  • 403
3 votes
2 answers
1k views

Can the number of CPU cores be reduced for a CentOS virtual machine?

Our VMware admins tell me that we can add additional virtual CPU cores to our VM's, but they tell me that we can't reduce the number of virtual CPU cores. One recently stated, "CPU on the other hand ...
Will's user avatar
  • 31
0 votes
1 answer
7k views

Maximum number of virtual CPU for Windows 7/10 virtual machine

For a virtual machine running Windows 7/10, is there a maximum number of virtual CPU a hypervisor can assign to it? As hypervisor, consider VMware ESXi 5.5 or 6.0. Andrea
A M's user avatar
  • 157
3 votes
2 answers
82 views

How to project / measure physical host wait with multi-core guests in ESXi

I’ve heard that if you have a guest with N virtual cores under ESXi, the hypervisor waits for N total logical processors on the host to become available simultaneously before delegating work from the ...
Chris Tonkinson's user avatar
1 vote
1 answer
39 views

Analyze single CPUs activities instead of sum of total CPU for what is usefull for?

I'm building a monitor to track down all Linux /proc data that can be usefull to understand how the server is behaving. Still I cannot understand if I should track every single CPU (and in a virtual ...
Max Cuttins's user avatar
1 vote
1 answer
763 views

Best VMWare Esxi CPU Resource Allocation Policy

We have a machine with an 88-core CPU in our department. Imagine there are 11 researchers who want to use the machine whenever they have to test a new approach. We've made 11 VMs on VMWare ESXI host, ...
Ali Hashemi's user avatar
0 votes
2 answers
3k views

Microsoft Azure threads per core

I am looking at the Pricing guide for Microsoft Azure. https://azure.microsoft.com/en-us/pricing/details/virtual-machines/windows/ How many threads are working in the "F16" "Compute Optimized" ...
posfan12's user avatar
  • 105
0 votes
1 answer
404 views

VMWare Physical CPU to vCPU

We have VMWare hosts with 2 cpus each (that are hyperthreading). We freed up some licensing (2 core licenses) for SQL server and want to upgrade from 4 to 6 cores. From my understanding, for SQL ...
Wes's user avatar
  • 111
0 votes
1 answer
758 views

Decreasing CPU allocation to running Guest Windows server

I have Ubuntu 16.04 as host and windows server 2012 as the guest installed using Virtio drivers in KVM. I am able to increase the CPU while guest is running, however I am not able to decrease the CPU'...
raks's user avatar
  • 103
12 votes
1 answer
2k views

KVM Host with 88 physical cores uses only 14 on 64 core Guest

I do have a server with 2 CPUs (22 Cores each plus HT). I created a KVM Guest with 64 allocated cores. When I run a compilation task the virtual machine shows all 64 cores at 100% (at moderate Disk I/...
HibikiTaisuna's user avatar
2 votes
2 answers
823 views

Configuring a 1-to-1 allocation of virtual processors

I have a question regarding a recommendation for setting up vCPU on a hyper-v virtual server. Documentation for the application states "For best performance, configure a 1-to-1 allocation of virtual ...
gBrner's user avatar
  • 51
4 votes
1 answer
6k views

Oversubscription vs Over allocation of vCPU resources in vSphere

I'm trying to understand over allocation of vCPU compared to over subscription of vCPU. For the purposes of the question lets assume the host that I will be using has a 16 core Xeon(2.1Ghz). Based ...
seelani's user avatar
  • 41
6 votes
3 answers
3k views

VMware / SQL - physical vs logical cores - how many vCPUs to assign when HT is enabled

We have a ESX host: It has 2 CPU x 8 cores each, and HT enabled. So, total 16 physical cores or 32 logical cores. It has a single dedicated SQL VM on it (no other VMs run on this host), and it has ...
d-_-b's user avatar
  • 191
0 votes
0 answers
361 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
0 votes
1 answer
76 views

Does turning off vCPU in Ubuntu 14.04 impact vmware's cpu scheduler?

I have a Ubuntu VMWare VM that was given 6 CPUs, but rarely sees a load above 1. It is running in a vSphere 5.5 cluster. Nowing that VMWare's CPU scheduler has to clear 6 CPUs for processing this VM,...
flickerfly's user avatar
  • 2,823
3 votes
1 answer
5k views

Calculation of virtual resources

I virtualized a server using VMware ESXi. My virtual machine has 8 vCPU, while the real processor is an Intel Xeon E5-2620 v3 (6 core) @ 2,4 GHz. In order to estimate virtual resources needed for ...
A M's user avatar
  • 157
2 votes
1 answer
2k views

t2.micro instance is always below baseline CPU usage but still consumes CPU credits - why?

I have a t2.micro instance running Ubuntu Linux on ec2 in Ireland, it's running batch jobs and I've tuned them so that the max CPU is pretty low - it never exceeds 10%. The docs say that: When a ...
A E's user avatar
  • 148
-1 votes
1 answer
10k views

How vCPUs are calculated?

Yesterday I contacted my vendor to buy a server, and I asked them how I should calculate the CPU and RAM requirements for my server, given that I want to create multiple virtual servers on it He said ...
washaq's user avatar
  • 21
2 votes
3 answers
98 views

How can I keep a third-party cloud provider accountable for guest VM performance?

I support an ERP system for a manufacturer. We're experiencing intermittent application performance issues on our database, hosted on VMware by a third-party cloud provider. (They're a smaller ...
durette's user avatar
  • 164
2 votes
1 answer
4k views

CPU frequency governor for virtualized guest in VMware

CPU frequency governor can scale the CPU frequency up or down in order to save resources. In a physical server usually have sense, but I don't know if this is applicable for a virtual guest running ...
rfmoz's user avatar
  • 792
0 votes
1 answer
391 views

Xen reduce VCPU

I am trying to reduce the number of VCPU on Dom0, but not understanding why its not reducing the number. Log: [2016-02-11 13:43:25 2550] INFO (XendDomainInfo:1977) Set VCPU count on domain Domain-0 ...
user3580316's user avatar
0 votes
0 answers
527 views

XenServer 6.2 VM Performance (SSD, RAID-10, Quad-core)

Greetings everyone :) My configuration is the following: HP C3000 tower enclosure 1st HP Proliant BL460 G1 quad core xeon 2.66GHz 12MB L2 cache, 24GB RAM, BIOS I15 5/2/2011 partnered with HP ...
3a2roub's user avatar
  • 294
1 vote
2 answers
389 views

What does take all the cpu here?

On a small SSD VPS I got 2 GB of RAM and 2 vCPU core (dedicated to my server), virtualized via KVM. So far so good. The server is mainly used for databases (MySQL) and fast network file storage (via ...
Bent's user avatar
  • 328
18 votes
3 answers
130k views

Understanding the VMware ESXi limitations of the free Version

I am running an ESXi Vsphere Client Version 6.0.0 but with all the different documentation and changes I have trouble to understand my limitations. From the official documentation I see that my limit ...
RayofCommand's user avatar
  • 1,451
0 votes
0 answers
251 views

VPS Server shoots to 900% CPU Utilisation for 10 to 15 minutes

I've just taken a VPS Server with Assured 1 core AMD opetron and burstable to 8 cores. RAM is 5 GB Average Usage so far been around 1 Cpu, but at a point of time - when checked through monitoring - ...
Ruchika's user avatar
  • 101
1 vote
2 answers
5k views

Virtualization: vCPU pinning with Hyperthreading Host CPU?

I'm using KVM/libvirt on a Linux server with Core i7-2600 CPU, which has the following CPU topology (1 Socket, 4 Cores, 8 Threads): Physical | Logical ---------+-------- Core 0 | 0, 4 Core 1 | 1, ...
lynix's user avatar
  • 55