Public bug reported: It is a very strange problem.
I have a new DELL PowerEdge R470 installed with Ubuntu 24.04 updated to the last level (at the time 24.04.02 / 6.8.0-54-generic). The DELL PowerEdge R470 has a bridge and KVM installed. If I start a new virtual machine with vanilla Ubuntu 24.04.0, everything is fine, also with Ubuntu 22.04.xx virtual machines the situation is OK. But as soon as I update an Ubuntu 24.04 VM (with apt update && apt upgrade) the networking speed after the reboot of the VM is tremendously slow. It plummets to 50 KB/s for all protocols (http, ssh ecc.) both in uplad and downalod. This problem affect only the upgraded virtual machine, the others VM are still fast. The strange thing is if I migrate the VM to another host (same configuration of Ubuntu/KVM/Bridge) the VM is OK, and if a return the VM to the orginal host the problem presents itself again. The problem is reproducible with: virt-install \ -n srv-test \ --description "Paperless Delivery Notes" \ --os-variant=ubuntu24.04 \ --ram=4096 \ --vcpus=4 \ --disk path=/kvm/images/srv-test/srv-test.qcow2,format=qcow2,bus=virtio,size=200 \ --network bridge:br0 \ --graphics vnc,listen=0.0.0.0,port=5901 \ --noautoconsole \ --autostart \ --cdrom /kvm/iso/ubuntu-24.04-live-server-amd64.iso ** Affects: kvm (Ubuntu) Importance: Undecided Status: New ** Tags: regression-update -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2100717 Title: Networking speed is slow on KVM Virtual Machine running upgraded Ubuntu 22.04.02 Software To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/2100717/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs