Large named.run file

Sounds like you might have started named in debug mode, which can cause large named.run files. By default named saves debug information to /var/named/named.run file. You can stop writing to it by disabling debug mode.

To check that your named is running without the debug option:

ps -aux | grep named

You may get a response like this

named -d 3 -c /etc/named-master.conf

If the -d flag exists try to restart named without it and check again

With regards to the named.run file, it is safe to delete but you need to stop named first.

Other useful info:

rndc notrace  # will disable debug in bind
rndc reload   # will reopen file handles