nginx 0.8.25 on an Xen VPS - Ubuntu.

[st1905]

The very same issue is described here and solution was given by Maxim.

[quote="nginx binary was compiled with file aio support , but your
system doesn't have proper interfaces (lacks eventfd() syscall). 
Solution is to recompile nginx without file aio support. "]

[/quote]

More at here http://forum.nginx.org/read.php?2,150853,150853#msg-150853

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,23577,153119#msg-153119