Very slow network speed on VMs

[ggroke]

Hi there,

I'm running a PVE 7.1-7 and I'm experiencing very slow network speeds on VMs. My host: Dell R710, Dual socket Xeon X5670, 48 Gb RAM, and dual 10 Gb network card, which are bridged (aggregated), making 20 Gb . However, on VMs I can't get more than 300 kbps.

There are currently 6 VMs running: 4 Linux + 2 Windows Servers.

I've tried E1000, VirtIO but it doesn't seem to have any effect at all.

Is there anything I can try?

 

[Moayad]

Hi,

What looks the PVE network configuration like?

How you test the network speed on the VMs (using iPerf)? If so, please provide us the result of the testing!

BTW: the new version of PVE 7.2 is available

 

[sojic]

eno1 and eno2 interfaces are 100Mbps
All others (tap) are 10Mbps





Testing in local network (copying files over NFS to storage).


Config file:

root@ve1:/etc/pve/lxc# cat 104.conf
arch: amd64
cores: 4
hostname: xxxxx
memory: 2048
nameserver: 1.1.1.1
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.35.1,hwaddr=92:FD:D9:F7:C9:45,ip=192.168.35.5/24,type=veth
onboot: 1
ostype: ubuntu
rootfs: local-zfs:subvol-104-disk-0,size=10G
swap: 512
unprivileged: 1

 

[iniciaw]

Use iperf first to discard network and after this check NFS configurations maybe you are missed some NFS tricks.
If problem is network could be long ethernet cable, bad router, bad server drivers... After this checked and ok, continue with another missconfigurations.

You can't make a serious check using a NFS transfer speed.

 

[sojic]

Use iperf first to discard network and after this check NFS configurations maybe you are missed some NFS tricks.
If problem is network could be long ethernet cable, bad router, bad server drivers... After this checked and ok, continue with another missconfigurations.

You can't make a serious check using a NFS transfer speed.

The issue is not related with NFS. NFS is mounted into the virtual machine/container.
The screenshot I have sent is from the host (proxmox).

As I mentioned, the "real" network interfaces (eno1 and eno2) are 100Mbps.

The virtual network interfaces, assigned to VM/CT are 10Mbps. This issue is not related with cable, or NFS protocol.