Tor relay on vserver exeeding numtcpsock

Thomas S. Benjamin tomb at
Thu Jan 13 00:02:08 UTC 2011

I believe that Klaus is already planning to contact his ISP, and was
seeking to learn more about reasonable values for numtcpsock.
Unfortunately different ISPs do this in different ways, and some
cannot easily change just that parameter in isolation.  Before paying
much money for a numtcpsock increase (my ISP charges a lot for this)
it is worth considering whether the increase in numtcpsock will
greatly increase the utility of the relay.  If the numtcpsock increase
is cheap or free, then of course one would go for the most sockets one
can get.

In my case I find that when I trim my bandwidth to about what I can
afford per month I need ballpark of the number of sockets that I am
currently permitted.  Unfortunately this balance changes with each new
version of Tor.  I'm not exactly sure why, but I wonder whether
performance improvements mean that I can handle more circuits at a
time, making the number of sockets the limiting factor again.  Does
anybody here know whether this is so?

On Wed, Jan 12, 2011 at 4:44 PM, Moritz Bartl <moritz at> wrote:
> Hi,
> You should probably contact the ISP first to see if they will raise the
> limit. Mine was low on file descriptors and they upped it generously 5
> minutes later (on a cheap $20 vserver).
> Moritz
> On 12.01.2011 22:02, coderman wrote:
>>> "Error creating network socket: No buffer space available"
>>> errors. The numtcpsocks parameter limit is set to 550 on the vserver.
>> 550 is ridiculous. it should be at least 4096, more if they are accomodating.
>> good luck!  you may want to update the good / bad ISP entry with your
>> experience.
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Sincerely Yours,
              ---Thomas S. Benjamin
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