Slow internet on VM

J

jeff7daniels

New Member
Nov 24, 2023
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Hello,

I have a problem with ProxMox and download speed on VM. Download speed is about 10Mbps. Reinstalled driver for VirtIO but not helped.

EDIT: Using Debian
 
Last edited:
Hello,

here is my interfaces file


Code: 
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface enp24s0f0 inet manual

iface enp24s0f1 inet manual

auto vmbr0
iface vmbr0 inet static
    address 18x.21x.13x.99/25
    gateway 18x.21x.13x.1
    bridge-ports enp24s0f0
    bridge-stp off
    bridge-fd 0

auto vmbr1
iface vmbr1 inet static
    address 10.20.30.1/24
    bridge-ports enp24s0f1
    bridge-stp off
    bridge-fd 0
    post-up iptables -t nat -A POSTROUTING -s '10.17x.15x.0/24' -o vmbr0 -j MASQUERADE
    post-down iptables -t nat -D POSTROUTING -s '10.17x.15x.0/24' -o vmbr0 -j MASQUERADE


# source /etc/network/interfaces.d/*

VM config


Code: 
boot: order=ide0;ide2;net0
cores: 4
ide0: local:101/vm-101-disk-0.qcow2,size=50G
ide2: none,media=cdrom
machine: pc-q35-7.2
memory: 8096
meta: creation-qemu=7.2.0,ctime=1698767937
name: p.l
net0: virtio=C6:10:FE:67:C5:73,bridge=vmbr1
numa: 0
ostype: win10
scsihw: virtio-scsi-single
smbios1: uuid=70be3a3d-9f65-4740-b0ba-478b638b8bd7
sockets: 2
vga: virtio
vmgenid: 0cd832a8-2f92-49ec-beba-7a3b6bd047d5

I have noticed when I shut down specific VM download speed back to normal 1Gbps. I change port for this VM then everything works well and after 1 day make me a same problem.
 
Last edited:
Hi,

Thank you for the output!

Since it's a Windows VM I would check the [0] Windows guest best practices.

In order to narrow down the issue if the issue related to the VM config or the Network config, I would ask you if any other VM/CT have the same issue. If only the 101 VM has this issue, I would follow our wiki below link.

[0] https://pve.proxmox.com/wiki/Windows_10_guest_best_practices
 
Thank you for reply. All VM's have same issue. And on server side download speed drops when specific VM is on. When I shutdown this specific VM download speed back to normal. I can send all VM's configs
 
Yes, all VMs are Windows based. I installed one VM and clone it for other. One thing which I edit Machine: from Default (i440fx) to q35 7.2 and I change it manually for each. I did it because have some input lag on VMs but after this works well for couple of weeks, and now have this problem with download speed.
 
Hello @Moayad,

after following this steps I don't have internet access on my VM, driver is installed, IP set for Ethernet.

This is my route.v4 file

Code: 
# Generated by iptables-save v1.8.7 on Wed Aug  3 18:01:09 2022
*nat
:PREROUTING ACCEPT [2131:378572]
:INPUT ACCEPT [68:8573]
:OUTPUT ACCEPT [25:2277]
:POSTROUTING ACCEPT [48:3437]
-A POSTROUTING -s 10.20.30.0/24 -o vmbr0 -j MASQUERADE
-A PREROUTING  -p tcp -m tcp --dport 3389 -j DNAT --to-destination 10.20.30.10:3389
-A PREROUTING  -p tcp -m tcp --dport 3311 -j DNAT --to-destination 10.20.30.11:3389
-A PREROUTING  -p tcp -m tcp --dport 3312 -j DNAT --to-destination 10.20.30.12:3389
-A PREROUTING  -p tcp -m tcp --dport 3313 -j DNAT --to-destination 10.20.30.13:3389
-A PREROUTING  -p tcp -m tcp --dport 3314 -j DNAT --to-destination 10.20.30.14:3389
-A PREROUTING  -p tcp -m tcp --dport 3315 -j DNAT --to-destination 10.20.30.15:3389
COMMIT
# Completed on Wed Aug  3 18:01:09 2022
# Generated by iptables-save v1.8.7 on Wed Aug  3 18:01:09 2022
*raw
:PREROUTING ACCEPT [12236:2266130]
:OUTPUT ACCEPT [2875:2238914]
COMMIT
# Completed on Wed Aug  3 18:01:09 2022
# Generated by iptables-save v1.8.7 on Wed Aug  3 18:01:09 2022
*filter
:INPUT ACCEPT [3087:616338]
:FORWARD ACCEPT [43:2360]
:OUTPUT ACCEPT [2875:2238914]
COMMIT
# Completed on Wed Aug  3 18:01:09 2022

For this new VM used 10.20.30.14 IP. With previous installation process internet works but have a problem with download speed.

I have one VM and when turn off this VM download speed back to normal.

EDIT:

here is intefaces

Code: 
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface enp24s0f0 inet manual

iface enp24s0f1 inet manual

auto vmbr0
iface vmbr0 inet static
    address 18x.21x.13x.9x/25
    gateway 18x.21x.13x.1xx
    bridge-ports enp24s0f0
    bridge-stp off
    bridge-fd 0

auto vmbr1
iface vmbr1 inet static
    address 10.20.30.1/24
    bridge-ports enp24s0f1
    bridge-stp off
    bridge-fd 0
    post-up iptables -t nat -A POSTROUTING -s '10x.17x.15x.0/24' -o vmbr0 -j MASQUERADE
    post-down iptables -t nat -D POSTROUTING -s '10x.17x.15x.0/24' -o vmbr0 -j MASQUERADE


# source /etc/network/interfaces.d/*


1701703814981.png
 
Last edited:
Hi,

this is config for VMID 104 which is created with guide https://pve.proxmox.com/wiki/Windows_10_guest_best_practices and this VM don't have internet access


Code: 
agent: 1
boot: order=scsi0;ide2;net0;ide0
cores: 4
ide0: local:iso/virtio-win-0.1.240.iso,media=cdrom,size=612812K
ide2: local:iso/Win10_22H2_EnglishInternational_x64v1.iso,media=cdrom,size=5991830K
machine: pc-i440fx-7.2
memory: 8192
meta: creation-qemu=7.2.0,ctime=1701690698
name: test
net0: virtio=4A:DE:82:80:76:F5,bridge=vmbr1,firewall=1
numa: 0
ostype: win10
scsi0: local:104/vm-104-disk-0.qcow2,cache=writeback,discard=on,iothread=1,size=50G
scsihw: virtio-scsi-single
smbios1: uuid=381132e9-d8dd-42e1-94ba-7e413c89b5e4
sockets: 2
vmgenid: d44b5d34-c48e-42ca-ba16-c6906e75388c

and this is conf for 105 using IP address 10.20.30.15 and if I turn off this VM, download speed back to normal.

Code: 
boot: order=ide0;ide2;net0
cores: 4
ide0: local:105/vm-105-disk-0.qcow2,size=50G
ide2: none,media=cdrom
machine: pc-q35-7.2
memory: 8192
meta: creation-qemu=7.2.0,ctime=1698767937
name: al.re
net0: virtio=3A:2A:FF:9E:67:16,bridge=vmbr1
numa: 0
ostype: win10
scsihw: virtio-scsi-single
smbios1: uuid=ff096c1f-a4da-4893-9af7-5568694880e5
sockets: 2
vga: virtio
vmgenid: f2bd53b0-f0fe-4075-acac-76a740df1c1b


VM ID 105 have internet access and use IP 10.20.30.15 but when this VM is on all other VM's have a problem with download speed.
 
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Yes, VirtIO correctly installed, I have Ethernet but don't have internet access. Rate limit is just for testing here, don't look at this.
 
Yes, I tried to set manually. For all other VM's with different settings it is set manually and have internet access but I don't know why internet speed drop. It drop on whole server not only on VM's.
 
maybe you can tell us about your network topology and your switch model type
and your NIC port enp24s0f0 , enp24s0f1 plug into the same switch or not?
 
I really don't know about that, this is infrastructure from datacenter hosting company. How can I know that? What exactly I need to ask server provider?
 
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