Slow network speed on VMs, but not on host

My ethernet controller is RTL8111

Code:
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 08)
00:02.0 VGA compatible controller: Intel Corporation Device 5906 (rev 07)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:14.0 USB controller: Intel Corporation Sunrise Point-LP USB 3.0 xHCI Controller (rev 21)
00:14.2 Signal processing controller: Intel Corporation Sunrise Point-LP Thermal subsystem (rev 21)
00:15.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #0 (rev 21)
00:15.1 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO I2C Controller #1 (rev 21)
00:16.0 Communication controller: Intel Corporation Sunrise Point-LP CSME HECI #1 (rev 21)
00:17.0 SATA controller: Intel Corporation Sunrise Point-LP SATA Controller [AHCI mode] (rev 21)
00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #4 (rev f1)
00:1c.5 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #6 (rev f1)
00:1e.0 Signal processing controller: Intel Corporation Sunrise Point-LP Serial IO UART Controller #0 (rev 21)
00:1f.0 ISA bridge: Intel Corporation Sunrise Point LPC Controller/eSPI Controller (rev 21)
00:1f.2 Memory controller: Intel Corporation Sunrise Point-LP PMC (rev 21)
00:1f.3 Audio device: Intel Corporation Sunrise Point-LP HD Audio (rev 21)
00:1f.4 SMBus: Intel Corporation Sunrise Point-LP SMBus (rev 21)
01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
02:00.0 Network controller: Intel Corporation Wireless 3165 (rev 81)
 
I keep reading up about it, and could be new kernel and intel NICs, I've got i219-v, my brother just realised he's got same issue with i218-v. Will try new driver sometime this week.

What's yours?
Code:
lspci
My ethernet controller is RTL8111
 
I keep reading up about it, and could be new kernel and intel NICs, I've got i219-v, my brother just realised he's got same issue with i218-v. Will try new driver sometime this week.

What's yours?
Code:
lspci
My bandwidth is 200M, after my test, Debian 11.1 and Ubuntu 21.10 download speed is 12MB/s or 100Mbps on the internet, but the Fedora 35 download speed is 27.4 MB/s or 200Mbps.

lspci show the ethernet is same. o_O

01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 15)
 
I'm confused! :rolleyes:
Quite a few people out there (google: debian 11 slow internet) with similar issues. Looks as it's not only my Intel NICs but RTL also.

Hmhh....
 
I can confirm some trouble with network speed, in particular in VMs. LXC containers are not affected. I tried E1000, virtio and RTL8139 network adapters in VM, virtio is the fastest, but got only max 460Mb/s from 1000Mb/s available. Very strange. Maybe a bug in newer kernel/qemu versions?

Not sure (and not benchmarked) but the 9p protokoll (to mount a shares in VMs) feels very slower too.

Code:
proxmox-ve: 7.0-2 (running kernel: 5.11.22-7-pve)
pve-manager: 7.0-14 (running version: 7.0-14/a9dbe7e3)
pve-kernel-helper: 7.1-4
pve-kernel-5.11: 7.0-10
pve-kernel-5.4: 6.4-5
pve-kernel-5.11.22-7-pve: 5.11.22-12
pve-kernel-5.11.22-5-pve: 5.11.22-10
pve-kernel-5.11.22-4-pve: 5.11.22-9
pve-kernel-5.4.128-1-pve: 5.4.128-2
pve-kernel-5.4.73-1-pve: 5.4.73-1
ceph-fuse: 14.2.21-1
corosync: 3.1.5-pve2
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown: residual config
ifupdown2: 3.1.0-1+pmx3
ksm-control-daemon: 1.4-1
libjs-extjs: 7.0.0-1
libknet1: 1.22-pve2
libproxmox-acme-perl: 1.4.0
libproxmox-backup-qemu0: 1.2.0-1
libpve-access-control: 7.0-6
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.0-12
libpve-guest-common-perl: 4.0-2
libpve-http-server-perl: 4.0-3
libpve-storage-perl: 7.0-13
libqb0: 1.0.5-1
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 4.0.9-4
lxcfs: 4.0.8-pve2
novnc-pve: 1.2.0-3
proxmox-backup-client: 2.0.13-1
proxmox-backup-file-restore: 2.0.13-1
proxmox-mini-journalreader: 1.2-1
proxmox-widget-toolkit: 3.3-6
pve-cluster: 7.0-3
pve-container: 4.1-1
pve-docs: 7.0-5
pve-edk2-firmware: 3.20210831-1
pve-firewall: 4.2-5
pve-firmware: 3.3-3
pve-ha-manager: 3.3-1
pve-i18n: 2.5-1
pve-qemu-kvm: 6.1.0-1
pve-xtermjs: 4.12.0-1
qemu-server: 7.0-18
smartmontools: 7.2-pve2
spiceterm: 3.2-2
vncterm: 1.7-1
zfsutils-linux: 2.1.1-pve1
 
Last edited:
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I've upgraded kernel to 5.15 now (https://github.com/fabianishere/pve-edge-kernel, still same issue. I've got gigabit fibre broadband.

1638372257469.png
1638372437532.png
Local network is fine, tested with iperf (local and internet). Local devices plugged into the router are also fine reporting gigabit broadband.

just don't know what else I can try, apart from reverting back to an older kerbel used in pve6 as this is when my host, conainers and VMs were reporting full speeds.
 
I have also tried I tried E1000, virtio and RTL8139. Between two VM's on the same host I typically get 100mbit, on some VM's i got 450mbit, the most I have measured with iperf3 is 450mbit with virtio, but that is to physically machines on my LAN, or to my other proxmox.

This is between a windows10 VM and the virtual FW (pfsense) on the same host. (PVE v. 7.1-10) both running virtio NIC's

Connecting to host 10.0.3.186, port 5201
[ 5] local 10.0.3.3 port 26461 connected to 10.0.3.186 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 11.7 MBytes 97.8 Mbits/sec 0 181 KBytes
[ 5] 1.00-2.00 sec 11.4 MBytes 95.9 Mbits/sec 0 209 KBytes
[ 5] 2.00-3.00 sec 11.4 MBytes 95.9 Mbits/sec 0 209 KBytes
[ 5] 3.00-4.00 sec 11.3 MBytes 95.0 Mbits/sec 0 209 KBytes
[ 5] 4.00-5.00 sec 11.4 MBytes 95.8 Mbits/sec 0 209 KBytes
[ 5] 5.00-6.00 sec 11.4 MBytes 96.0 Mbits/sec 0 209 KBytes
[ 5] 6.00-7.00 sec 11.4 MBytes 95.8 Mbits/sec 0 209 KBytes
[ 5] 7.00-8.00 sec 11.4 MBytes 96.0 Mbits/sec 0 209 KBytes
[ 5] 8.00-9.00 sec 11.3 MBytes 95.1 Mbits/sec 0 209 KBytes
[ 5] 9.00-10.00 sec 11.4 MBytes 95.7 Mbits/sec 0 209 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr
[ 5] 0.00-10.00 sec 114 MBytes 95.9 Mbits/sec 0 sender
[ 5] 0.00-10.00 sec 114 MBytes 95.9 Mbits/sec receiver

iperf Done.
 
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Is the problem still relevant? I have same problem. I have 160 Mbps and unlimited upload. Let's take it as 1 Gbps.

When I run "speedtest" in PVE shell, it's show me nice speed for upload (I have 200 VM's, because of this download is ok):

Screenshot(2).png

But when I run test in VM i get this: scren2.png

I think this is not a normal situation. In general, here and on other forums, I have seen a lot of Proxmox users with this kind of problem. And in general, it seems that the internet speed in VMs is much lower, just from the terminal sometimes. I see that there is no specific reason for this. Some say that there is an effect when replacing kvm64 processor type with host, others say something else, but in the absolute majority this problem remains as it is.
 
Is the problem still relevant? I have same problem. I have 160 Mbps and unlimited upload. Let's take it as 1 Gbps.

When I run "speedtest" in PVE shell, it's show me nice speed for upload (I have 200 VM's, because of this download is ok):

View attachment 38983

But when I run test in VM i get this: View attachment 38986

I think this is not a normal situation. In general, here and on other forums, I have seen a lot of Proxmox users with this kind of problem. And in general, it seems that the internet speed in VMs is much lower, just from the terminal sometimes. I see that there is no specific reason for this. Some say that there is an effect when replacing kvm64 processor type with host, others say something else, but in the absolute majority this problem remains as it is.
Hi @Orkhan ,

Not sure what's your situation, but this did the trick in my situation.

https://forum.proxmox.com/threads/langsame-verbindung-ins-wan-im-lan-alles-gut.100500/#post-436011

I'm getting full 900Mbps in CT/VM on my 900Mbps broadband.

Good luck
 
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Last edited:
Hi @LoleUK!

My problem is that, in PVE host (shell) and CT I get nice speed. But in VM it's very slow. For example my upload is unlimited, but I get from 18 to 310 Mbps in max (upload) in VM.
And you are using virtio and not E1000 as the virtual NIC? E1000 is known to be slow as it is fully emulated and not paravirtualized like virtio.
 
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It would be great if someone with a greater knowledge of the internals and how things have changed from Proxmox 6 to 7 could look into this deeper and come up with a real answer. Our VMs are MUCH slower since Proxmox 7 and even more so since 7.2 .. Proxmox 6 was like a race car now we feel like we are in a Ford Fiesta ..

Thanks

I didn't put any numbers because we are seeing what the others in this post are seeing. We are also using virtio on everything. We don't use containers. We've never used e1000 for NIC except maybe more than 10 years ago when we first started using Proxmox on version 2.0.
 
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have the same issue here, the iperf3 showing the LAN speed is 2.3G
Bash:
Connecting to host 192.168.1.31, port 5201
[  4] local 192.168.1.47 port 7596 connected to 192.168.1.31 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec   278 MBytes  2.33 Gbits/sec
[  4]   1.00-2.00   sec   268 MBytes  2.25 Gbits/sec
[  4]   2.00-3.00   sec   278 MBytes  2.33 Gbits/sec
[  4]   3.00-4.00   sec   274 MBytes  2.30 Gbits/sec
[  4]   4.00-5.00   sec   274 MBytes  2.30 Gbits/sec
[  4]   5.00-6.00   sec   275 MBytes  2.31 Gbits/sec
[  4]   6.00-7.00   sec   276 MBytes  2.31 Gbits/sec
[  4]   7.00-8.00   sec   270 MBytes  2.27 Gbits/sec
[  4]   8.00-9.00   sec   278 MBytes  2.33 Gbits/sec
[  4]   9.00-10.00  sec   247 MBytes  2.08 Gbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  2.66 GBytes  2.28 Gbits/sec                  sender
[  4]   0.00-10.00  sec  2.66 GBytes  2.28 Gbits/sec                  receiver


iperf Done.

But the speedtest CLI showing only 380 Mbps download speed
Bash:
Speedtest by Ookla


      Server: Scaleway - Vitry-sur-Seine (id: 5022)
         ISP: Free SAS
Idle Latency:     2.81 ms   (jitter: 0.21ms, low: 2.55ms, high: 3.14ms)
    Download:   383.08 Mbps (data used: 321.5 MB)                                                 
                  2.61 ms   (jitter: 0.34ms, low: 2.13ms, high: 3.25ms)
      Upload:   672.78 Mbps (data used: 331.0 MB)                                                 
                  5.09 ms   (jitter: 0.45ms, low: 3.15ms, high: 5.85ms)
 Packet Loss:     0.0%
  Result URL: https://www.speedtest.net/result/c/89215d31-e6d3-443d-b229-f07f262f8e92

While in a windows vm, it can correctly shows it's downloading over 1G speed


Update:
turned out to be a speedtest server issue, need to indicate a server that has muilti gig capabilities.
Bash:
user@pve:~$ speedtest -s 45202


   Speedtest by Ookla


      Server: Appliwave - Croissy-Beaubourg (id: 45202)
         ISP: Free SAS
Idle Latency:     3.92 ms   (jitter: 0.40ms, low: 3.58ms, high: 4.43ms)
    Download:  2248.61 Mbps (data used: 2.2 GB)                                                  
                  3.88 ms   (jitter: 0.19ms, low: 3.55ms, high: 4.74ms)
      Upload:   673.19 Mbps (data used: 320.6 MB)                                                  
                  6.30 ms   (jitter: 0.47ms, low: 4.32ms, high: 7.21ms)
 Packet Loss:     0.0%
  Result URL: https://www.speedtest.net/result/c/25930476-7a45-4b29-a949-6084a12b5eaa
 
Last edited:

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