Oracle KVM qemu-kvm: unable to map backing store for guest RAM: Cannot allocate memory"

 Oracle KVM Service fails to start with following error:

#virsh start db-node1

error: Failed to start domain 'db-node1'

error: internal error: QEMU unexpectedly closed the monitor (vm='db-node1'): 2024-04-08Tqemu-kvm: unable to map backing store for guest RAM: Cannot allocate memory

 

This issue is happening due to the wrong version of the packages:

 

# rpm -qa | grep qemu

qemu-img-8.0.0-16.el9_3.1.x86_64

libvirt-daemon-driver-qemu-9.5.0-7.0.1.el9_3.x86_64

qemu-kvm-tools-8.0.0-16.el9_3.1.x86_64

qemu-pr-helper-8.0.0-16.el9_3.1.x86_64

qemu-kvm-docs-8.0.0-16.el9_3.1.x86_64

ipxe-roms-qemu-20200823-9.git4bd064de.el9_0.noarch

qemu-kvm-common-8.0.0-16.el9_3.1.x86_64

qemu-kvm-device-display-virtio-gpu-8.0.0-16.el9_3.1.x86_64

qemu-kvm-ui-opengl-8.0.0-16.el9_3.1.x86_64

qemu-kvm-ui-egl-headless-8.0.0-16.el9_3.1.x86_64

qemu-kvm-device-display-virtio-gpu-pci-8.0.0-16.el9_3.1.x86_64

qemu-kvm-block-blkio-8.0.0-16.el9_3.1.x86_64

qemu-kvm-block-rbd-8.0.0-16.el9_3.1.x86_64

qemu-kvm-device-display-virtio-vga-8.0.0-16.el9_3.1.x86_64

qemu-kvm-device-usb-host-8.0.0-16.el9_3.1.x86_64

qemu-kvm-device-usb-redirect-8.0.0-16.el9_3.1.x86_64

qemu-kvm-audio-pa-8.0.0-16.el9_3.1.x86_64

qemu-kvm-core-8.0.0-16.el9_3.1.x86_64

qemu-kvm-8.0.0-16.el9_3.1.x86_64

 

Solution:

 

Remove all wrong version of rpms and install new rpms using the correct version of repository:

 

$ cat etc/yum.repos.d/virt-ol9.repo

[ol9_kvm_utils]

name=Oracle Linux 9 KVM Utilities ($basearch)

baseurl=https://yum$ociregion.$ocidomain/repo/OracleLinux/OL9/kvm/utils/$basearch/

gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle

gpgcheck=1

 

 

Now you should be able to start the problematic VM without any issues.

 Hope it helps :)

regards,

ZAHEER