slow speed with virtio driver


New Member
Apr 25, 2018
Hello. I need help.
Have situation:
1. I copy file from proxmox-VM to interten-pc. When i have virtio driver for net-card i have bad speed (screen 1). When i change driver on e1000, then i have good speed (screen 2).

Screen 1



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VirtIO uses CRC offloading, which calculates the checksums on the real NIC.
Not all NICs support this feature, some NICs calculate wrong CRCs due to the different MAC address.

e1000 calculate these CRCs in the software emulation.
e1000 is a full emulation of the vNIC, VirtIO is a paravirtualised vNIC.

Do you have the latest stable VirtIO drivers installed in the guest and what network card is installed in your host?
Thank you for answer!
I have test on two servers.
1 server has card

2 server has card

Also i have openswitch and bond for two netcards.

cat /etc/network/interfaces

allow-vmbr0 bond0
iface bond0 inet manual
ovs_bonds enp1s0f0 enp1s0f1
ovs_type OVSBond
ovs_bridge vmbr0
ovs_options vlan_mode=native-untagged other_config:lacp-time=fast tag=1 lacp=active bond_mode=balance-tcp

auto lo
iface lo inet loopback

auto enp1s0f0
iface enp1s0f0 inet manual

auto enp1s0f1
iface enp1s0f1 inet manual

allow-vmbr0 vlan1
iface vlan1 inet static
ovs_type OVSIntPort
ovs_bridge vmbr0
ovs_options tag=1

auto vmbr0
iface vmbr0 inet manual
ovs_type OVSBridge
ovs_ports bond0 vlan1
> Do you have the latest stable VirtIO drivers installed in the guest and what network card is installed in your host?
No. I have VirtIO drivers from standart OS and had test on Debian 9 and Debian 10.


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