ethtool eth0 displays 1000Mb/s correctly, but shouldn't virtio 'virtual' network connections be x10 faster?

eugenevdm

Active Member
Dec 13, 2020
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My setup is:
  • A Proxmox VE host server with 1000Mb/s physical network card
  • An ZFS over iSCSI link to a virtual machine on the same host which is running TrueNAS Core. Virtio.
  • Numerous VMs all sharing the same NAS, mostly Debian derivatives. All Virtio
On the host:

# ethtool eth0
Settings for eth0:
...
Supported link modes: 1000baseT/Full
...
Advertised link modes: 1000baseT/Full
...
Speed: 1000Mb/s
Duplex: Full
Auto-negotiation: on

So clearly, I have a 1 gbit/s network card :)

This morning there was a race condition on one of the VMs running LAMP and ClamAV which meant it RAM quickly got depleted, then it's swap file, and from then it went into a no response memory race condition. Impossible to access SSH etc. I had to force stop the VM.

On the host, I see this:
download (1).png

On the VM with the race condition, I see this:91b20d3f-be3b-4779-965e-f0476324229c.png

So far everything is normal and I am not complaining. 99.9% of the time this solution works really well.

But here is my question:

Shouldn't the Proxmox VE host network connections to the virtual machines be "unlimited"? Or something more sane, like 10 gbit/s instead of 1 gbit/s? Surely this is "virtual"?