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

6
  • What's slow exactly?
    – gronostaj
    Nov 10, 2020 at 13:10
  • it took a long time to boot up and everything is slow to open . even a right click takes long time. i don't understand the reason behind the 100 percent cpu usage
    – munish
    Nov 10, 2020 at 13:15
  • Looks like NGEN is running. Wait for it to finish. Since you apparently created a new VM this is a weak comparison anyway.
    – Daniel B
    Nov 10, 2020 at 13:34
  • I don't think waiting is helping, something else is going on
    – munish
    Nov 10, 2020 at 13:57
  • have you tried running other oses like linux? Are they also slow like this ? you can also try using vmware workstations 16
    – Madhubala
    Nov 10, 2020 at 15:19

1 Answer 1

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.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .