How do you change tcp_congestion_control on OpenVZ?

Question

I have a network of OpenVZ machines that I am testing various congestion control methods on. I need to know how to change the congestion control. Currently I get nothing but permission denied. Is it even possible to change this on this sort of configuration?

[tylersc@center ~]$ sudo sysctl -w net.ipv4.tcp_congestion_control=reno
error: permission denied on key 'net.ipv4.tcp_congestion_control'
[tylersc@center ~]$ sudo sysctl net.ipv4.tcp_congestion_control
net.ipv4.tcp_congestion_control = cubic

Correction: OpenVZ not OpenVM

Can you tell us what "OpenVM" is supposed to be? – Michael Hampton Dec 10 '13 at 01:16 — Michael Hampton, Dec 10 '13 at 01:16
Sorry, meant to say OpenVZ. – Tyler Scott Dec 10 '13 at 01:30 — Tyler Scott, Dec 10 '13 at 01:30

score 3 · Accepted Answer · answered Dec 10 '13 at 01:32

3

OpenVZ is container-based, and as such, uses a shared kernel. Containers can only change a very small, restricted set of sysctls (which ones, unfortunately, aren't even documented). If you need to do this, you need to be using something other than OpenVZ.

answered Dec 10 '13 at 01:32

Michael Hampton

244,070
43
506
972

How do you change tcp_congestion_control on OpenVZ?

1 Answers1