port speed

aanoaa

New Member
Jan 5, 2019
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0
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hey guys, so I've been having a strange issue with VirtiO interface and I would like to know if someone knows how to fix this.

Once user uses the entire port speed with any application, server stops accepting any other connection in my case its SSH and is focused only on the application.
Someone knows how to fix this?
How to allocate/reserve X Mbps just for SSH?

Thank you
 

LnxBil

Well-Known Member
Feb 21, 2015
4,087
387
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Germany
Someone knows how to fix this?
This sounds very, very strange to me. Normally you will have automatic tcp congestion for connections, but nothing like this. It should never drop the connection at all.

Can you describe your VM and their settings. Are there firewall rules in place?

Best way is to get wireshark, tshark or plain tcpdump to capture all packages and analyse afterwards what happens on the network channel.

How to allocate/reserve X Mbps just for SSH?
Whereas this is possible, it is not easy and there exists no GUI in PVE for this. If you really want to look into this (has to be another problem), search for traffic shaping via tc.
 

aanoaa

New Member
Jan 5, 2019
4
0
1
29
This sounds very, very strange to me. Normally you will have automatic tcp congestion for connections, but nothing like this. It should never drop the connection at all.

Can you describe your VM and their settings. Are there firewall rules in place?
Best way is to get wireshark, tshark or plain tcpdump to capture all packages and analyse afterwards what happens on the network channel.



Whereas this is possible, it is not easy and there exists no GUI in PVE for this. If you really want to look into this (has to be another problem), search for traffic shaping via tc.
Well yeah, it does. I have no idea why.
It only happens with VMs which has limited speed under 20MB/s, I didn't tested into details. No firewalls were set. CPU from 1-8cores.
Also once speed limit is set for example to 5 or 10MB/s and you full the port it goes still higher and higher (5MB = 40Mbps and nload,dstat,vnstat is able to show 300Mbps and higher), on main server where is proxmox running shows real result.

And thanks, will take a look for the traffic shaping but guess the issue is somewhere else.

Additional informations: Once is the VM port full VNC is working, server is not laggy on VNC however no one is able to use ssh/sftp or any of those services.
I can normally run the same application on my dedicated servers and even it fills the entire port, I'm still able to join and use the server.
 
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