Not sure why, but it logs stuff to /var/log/messages.

[root@lgdrm404 cinder]# grep log /etc/cinder/cinder.conf |grep -v catalog |grep -vE "#"

log_dir=/var/log/cinder

use_syslog=False

san_login = admin

[root@lgdrm404 cinder]# rpm -qa |grep cinder

python-cinder-2014.2-0.2.b3.el7.centos.noarch

python-cinderclient-1.0.9-2.el7.centos.noarch

openstack-cinder-2014.2-0.2.b3.el7.centos.noarch