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aande

Member

From: munich

Registered: 2014-09-15

Posts: 2

[SOLVED] SSH painfully slow on VPS

I have a VPS server which is running a LEMP stack, mumble and team fortress 2 server.

However, recently SSH has been painfully slow, rendering it basically useless and the server unmaintainable. As this is a rented server, I have no physical access.

This is NOT the common problem with the slow login process that comes up when searching the internet for "slow ssh". I never had (and have) a problem with that.

The symptom is a painfully slow ssh, reacting to keypresses and displaying results after seconds (sometimes it's more than half a minute). SSH basically stops responding when doing stuff like viewing logs (involving a bit more traffic) so that I have to close the connection and reconnect. There are times when SSH works with normal speed but this usually lasts only few seconds. I could not see any pattern there.

What I have tried:
- flushing iptables with empty rules, so I can rule out networking problems
- load is not the problem either, it's usually around 0.45

The problem is persistent across reboots. I have NOT changed the configuration recently so it might have been a recent update that introduced this problem.

Unfortunately I cannot pin down the exact time, but the issue has arisen sometime in the past two weeks.

It would be great if someone has an idea, I am desperate at this point. If needed, I can provide any additional information.

Last edited by aande (2014-09-16 14:29:09)

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: [SOLVED] SSH painfully slow on VPS

Have you tried measuring the network performance with iperf? Maybe something along the way from you to the VPS is not working well. Also give mtr a try and see if at any point along the way you get high packet loss.

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R00KIE
Tm90aGluZyB0byBzZWUgaGVyZSwgbW92ZSBhbG9uZy4K

aande

Member

From: munich

Registered: 2014-09-15

Posts: 2

Re: [SOLVED] SSH painfully slow on VPS

I tried mtr and there seems to be no packet loss at all to my home ip.

However, after a bit more trial an error I have found the culprit.
The problem is my wireless connection (my work laptop runs windows 8.1). When I use a wired connection everything works fine.

Thanks for the help!