0

Old Host centos 8 :

old cpu : AMD Ryzen 3 2200g Quad-core (4 Core, 4 Threads) 3.50 Ghz Processor 
old ram : 2 x Corsair 8 GB Vengeance LPX DDR4 2400MHz
SATA 3 SSD

Guest : microsoft windows pro ( image format : qcow2 )
cpu given : 1 cores, 1 threads
ram given : 4 GiB
disk size : 70 GB
<domain type='kvm' id='1'>

New Host centos 8 :

Current cpu : Intel® Core™ i9-10900 Processor 20M Cache, up to 5.20 GHz ( base freq 2.8, 10 core, 20 threads )
current ram : 2 x Corsair 32 GB Vengeance LPX DDR4 3000MHz
SATA 3 SSD

Guest : microsoft windows pro ( image format : raw )
cpu given : 2 core, 4 threads
ram given : 8 GiB
disk size : 150 GB
<domain type='qemu' id='1'>

Why is my new guest slow even with better hardware?

Edit : It seems that this is because of 100 percent cpu, but i still dont understand. since i have just installed the guest enter image description here

munish
  • 1,023

1 Answers1

0

old one was running with KVM : <domain type='kvm' id='1'> the new one was running with qemu : <domain type='qemu' id='1'>

The below lines helped in what the problem was,

[msingh@localhost Compressed]$ virsh capabilities | grep kvm
      <baselabel type='kvm'>system_u:system_r:svirt_t:s0</baselabel>
      <emulator>/usr/libexec/qemu-kvm</emulator>
      <emulator>/usr/libexec/qemu-kvm</emulator>
[msingh@localhost Compressed]$ virt-host-validate
  QEMU: Checking for hardware virtualization                                 : PASS
  QEMU: Checking if device /dev/kvm exists                                   : FAIL (Check that the 'kvm-intel' or 'kvm-amd' modules are loaded & the BIOS has enabled virtualization)
  QEMU: Checking if device /dev/vhost-net exists                             : PASS
  QEMU: Checking if device /dev/net/tun exists                               : PASS
  QEMU: Checking for cgroup 'cpu' controller support                         : PASS
  QEMU: Checking for cgroup 'cpuacct' controller support                     : PASS
  QEMU: Checking for cgroup 'cpuset' controller support                      : PASS
  QEMU: Checking for cgroup 'memory' controller support                      : PASS
  QEMU: Checking for cgroup 'devices' controller support                     : PASS
  QEMU: Checking for cgroup 'blkio' controller support                       : PASS
  QEMU: Checking for device assignment IOMMU support                         : WARN (No ACPI DMAR table found, IOMMU either disabled in BIOS or not supported by this hardware platform)

[msingh@localhost Compressed]$ dmesg | grep kvm
[    4.057616] kvm: disabled by bios
[    4.103434] kvm: disabled by bios
[    4.153237] kvm: disabled by bios
[    4.189655] kvm: disabled by bios
[    4.226248] kvm: disabled by bios
[    4.255269] kvm: disabled by bios
[    4.280338] kvm: disabled by bios
[    4.304822] kvm: disabled by bios
[    4.329817] kvm: disabled by bios
[    4.354095] kvm: disabled by bios
[    4.380921] kvm: disabled by bios
[    4.407032] kvm: disabled by bios
[    4.434890] kvm: disabled by bios
[    4.461832] kvm: disabled by bios
[    4.501926] kvm: disabled by bios
[    4.531737] kvm: disabled by bios
[    4.556759] kvm: disabled by bios
[    4.582904] kvm: disabled by bios
[    4.610824] kvm: disabled by bios
[    4.640933] kvm: disabled by bios

i had to go and enable the KVM in bios as per How to enable hardware virtualization on Asus motherboard

and also, i uncommented options kvm_intel nested=1 in /etc/modprobe.d/kvm.conf

This simple change and i recreated the VM to use KVM instead of qemu as hypervisor.

Its running fine now.

munish
  • 1,023