IO Pressure Stall - Unexplained

[fiona]

Hi,
you probably just need to migrate/start the VMs fresh with the updated QEMU version:

pve-qemu-kvm (10.2.1-2) trixie; urgency=medium
...
  * fix misleading IO wait and pressure stall information (PSI) accounting
    with io_uring-based event loop. A drive with IO thread being idle resulted
    in nearly 100% IO pressure. This is resolved by telling io_uring to not
    count blocking waits towards the IO wait metric when the event loop is
    effectively idle.

 

[lslamp]

@fiona
are you saying to downgrade from pve-qemu-kvm (11.0.2-1) to pve-qemu-kvm (10.2.1-2) trixie

Sorry, also when researching how to install only pve-qemu-kvm (10.2.1-2) trixie I see that it mentions that I should also place the package on hold.

apt reinstall pve-qemu-kvm=10.2.1-2
apt-mark hold pve-qemu-kvm

what is the purpose of this.

Lawrence

 

[gfngfn256]

you probably just need to migrate/start the VMs fresh with the updated QEMU version

Based on the OP, that is unlikely as he recently fresh-booted VM 107 & he has pve-qemu-kvm: 11.0.2-1.

--- [1. HOST OS & KERNEL VERSION] ---
proxmox-ve: 9.2.0 (running kernel: 6.8.12-18-pve)
pve-manager: 9.2.4 (running version: 9.2.4/5e5ae681198514d4)
proxmox-kernel-helper: 9.2.0
proxmox-kernel-7.0: 7.0.14-3
proxmox-kernel-7.0.14-3-pve-signed: 7.0.14-3
proxmox-kernel-7.0.12-1-pve-signed: 7.0.12-1
proxmox-kernel-6.8: 6.8.12-29
proxmox-kernel-6.8.12-29-pve-signed: 6.8.12-29
proxmox-kernel-6.8.12-18-pve-signed: 6.8.12-18
proxmox-kernel-6.2.16-20-pve: 6.2.16-20
proxmox-kernel-6.2: 6.2.16-20
pve-kernel-6.2.16-3-pve: 6.2.16-3

Is there a reason you are still running kernel: 6.8.12-18-pve, or have you just never rebooted the PVE host?

 

[fiona]

@fiona
are you saying to downgrade from pve-qemu-kvm (11.0.2-1) to pve-qemu-kvm (10.2.1-2) trixie

No, I say the issue should be fixed for VMs started with QEMU package versions >= 10.2.1-2.

You can check the running version for the VM with qm status 107 --verbose | grep running-qemu

 

[lslamp]

After installing the previous version of pve-qemu-kvm=10.2.1-2 all the IO Pressure Stall alerts went away.

Thanks for the help.
Lawrence