Gluster users - May 2014 - gluster IRC and use systemtap can't output glusterfs backtrace

hi everyone!
I meet three question:

question one:

I use IRC client(mirc) config server is:  irc.freenode.net  or  irc.gnu.org
but always can't connect, follwing errors:
Connect retry #1 irc,freenode,net (6667) (dns pool)
unable to connect server (connect timed out)



question two:
I system is centos6.4?glusterfs version is 3.4.
I want to use systemtap watch glusterfs function backtrace,
when I configure glusterfs source code, execute the following operation:
./configure --enable--systemtap
but checking dtrace happen error?because in my system?no dtrace?my
question is --enable--systemtap why need dtrace?  it must have dtrace?

question three:
when I do io test in glusterfs client. I execute following command:
stap -d /usr/local/sbin/glusterfs --ldd -e 'probe
process("glusterfs").function("*"){print_ubacktrace()}'

the result is  there is nothing output, and  the stap command S state,
no return.

thank you answer me!