How to rotate logs

Hi, A quick question: how to rotate logs with FreeRadius? I am using the OS newsyslog (FreeBSD), but as a result, FreeRadius do not log in the rotated file and I need to restart the server. The problem seems to arise because I am using chroot. When the server is started, the log file is opened before the chroot, in the /var/log directory. But after that, the server can only open the new log file in the chroot/var/log Thanks in advance, olivier --