Can I delete cores samba files on centos and how to control their growing?

I am working with samba 4 and everything was fine, but today I couldn´t  put a new computer on a PDC.  Looking what could it be, I found that the machine with centos where  it is installed samba 4, did not have enough space on its main partition: "/".
 I deleted some files, empty some logs files, but  was still was not enough. So I looked more deeply and found cores files on /usr/local/samba/var/cores/smbd that was consuming almost all the  "/" partition on the machine. What are cores files? can I delete them? and how can I control them to not grow again, to do a kind of logrotate by the way.
Thank you all