posix_net_conf.sh is currently a wrapper for perftune.py script and perftune.py has to be at the same directory as posix_net_conf.sh. Fixes #2176. Signed-off-by: Vlad Zolotarov <vladz@scylladb.com> Message-Id: <1490020882-32361-1-git-send-email-vladz@scylladb.com>