I and gaining an ever expanding list of of core.mountd.12009999475 type files in my root directory? What are these? Can I just delete them?
What causes them to be created?
That's called a core file. When a process crashes (in this case, mountd) the system makes a copy of the process's memory space (core) and saves it to disk for later analysis by an administrator (you).
You can safely delete them. To disable them, use
Read more about core files at http://developers.sun.com/solaris/articles/manage_core_dump.html