[PVE-User] FreeBSD VM random high CPU/Disk IO

[Eneko Lacunza]

Hi Kris,

We have two pfSense VMs on PVE 7.1 clusters, we haven't seen this issue. 
Both VMs have Ceph storage (Pacific).

Did you check memory usage inside VM? If it's spawning new processes and 
not killing old ones, this seems a swaping issue?

El 14/1/22 a las 9:18, Kris von Mach | Swishmail.com via pve-user escribió:
> Hello,
>
> Since upgrading from Proxmox 6.4 to 7.1 I have experienced issues with 
> FreeBSD VM's. Please keep in mind that I had no issues on 6.4.
>
> When the issue occurs, Proxmox summary shows excessively high CPU and 
> Disk IO for the VM, network is normal. CPU shows at near 100% and Disk 
> IO shows at 2.5GB/sec. The VM itself shows regular low cpu usage and 
> keeps on spawning new processes and doesn't kill old ones, they keep 
> on deinit. And load average goes from below 1 to over 200. Nothing is 
> actually using any CPU, so this definitely seems like disk IO issue.
>
> There are no errors logged anywhere, on proxmox host or freebsd vm.
>
> This happens on both raw and qcow2 VM's. I have tried switching from 
> default io_uring to native and threads, as well as combinations of no 
> cache and writeback using VirtIO SCSI single.
>
> On FreeBSD vm, I have also tried different time counters from HPET, 
> TSC-low, to kvmclock.
>
> And I've disabled balloon memory just in case.
>
> I have also tried different CPU options from host, to actual host 
> processor to kvm64. It is happening on both Intel and Amd hosts, so 
> probably not related to CPU.
>
> This happens randomly, usually during busier times. Sometimes it 
> happens within few hours, sometimes it takes days to occur.
>
> I have also tried pve-kernel-5.13.19-1-pve and pve-kernel-5.15.7-1-pve.
>
> I believe this has something to do with the issue that was occurring 
> on Linux VM's with IO errors. pve-qemu-kvm_6.1.0-3 doesn't seem to fix 
> this issue on FreeBSD VMs.
>
> Only way that I could resolve it is to reboot the VM.
>
> Anything else I could try?
>
> This definitely seems like a bug, as it was working fine under Proxmox 
> 6.4.
>
> __
> Kris

Eneko Lacunza
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Binovo IT Human Project

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