Hello.

I need to run two nginx instances on one server (not two workers, but two master processes with their own number of workers each). The problem is that when nginx is compiled with aio support I can start only one instance. When I try to start the second one, only master process starts and these lines appear in error log:

[emerg] 12789#0: io_setup() failed (1: Operation not permitted)
...
[alert] 12715#0: worker process 12789 exited with fatal code 2 and can not be respawn
...

This happens even if aio directive isn't used in configuration.

My system is CentOS 5.5 with kernel 2.6.18-194.32.1.el5, I've tried nginx 1.0.0 and nginx 1.0.2

So, is it expected behavior (I don't know nginx and/or aio internals), or is it a bug in nginx or aio, and is there a way to start two nginx instances, both with aio support?