Shell - print system variables?

[Dariusz1989]

Hey

Say I have something like this in tunables :
net.inet.tcp.sendbuf_auto 1 sysctl

How can I go to shell and re-print that item parameter that is set in os? To be 2x sure its proper?

I read that some values if typed above the "limit" might default to default one and have no effect. I'm trying to tune up some tcp networking for 10gbe here.

Regards
Dariusz

 

[Chris Moore]

To view all readable variables: sysctl -a
To read a particular variable, specify its name: sysctl kern.maxproc

 

[dlavigne]

Hey

Say I have something like this in tunables :
net.inet.tcp.sendbuf_auto 1 sysctl

How can I go to shell and re-print that item parameter that is set in os? To be 2x sure its proper?

sysctl net.inet.tcp.sendbug_auto

Or, if you want to see a larger context:

sysctl -a |grep net.inet.tcp

I read that some values if typed above the "limit" might default to default one and have no effect. I'm trying to tune up some tcp networking for 10gbe here.

Where did you read that?

 

[Dariusz1989]

Where did you read that?

https://lists.freebsd.org/pipermail/freebsd-current/2011-February/022891.html

I noticed that I could increase it atmost to 128Kbytes (131072). Any value
above 128k, results in a failure to get the requested window size, resulting
in a failure of "iperf -s -w <windowsize>".

@Chris Moore Thanks ! & dlavigne !