I was having a maddening time with the diskless boot times on my MD in 810 (I am not sure if this is an issue unique to me or if other people are having the issue, so please let me know if anyone else had this problem, it isn't anywhere in the forums that I could find, but it is all over the Ubutnu forums)
Essentially upon booting my diskless MD's I would get an NIS bind failure that looks like
Starting NIS Services
binding to YP ...
... [repeat 10 times]
Along with this, starting cups, hal, and a few other services on the MD would hang forever. My MD boot times were on the order of about 8-10 mins (and these aren't little MD's, my main computer is a monster and it had the same problem) so I figured it had to be a networking issue.
Additionally, DNS lookups from MDs (like when doing an apt-get install on the MD) took forever (though oddly nslookup and dig were always responsive ~ms). And ssh moonXX would take ages to give me a command prompt (~3 mins from time I issued command from the core).
Looking at the /etc/nsswitch.conf file on the MD and core suggests that nis is used for host propagation, and given the dns issues it seemed likely that despite what many of the forums out there say about this binding to yp... failure, ypbind was never actually finding the NIS server on the core.
Furthermore, running ypbind -d on the core would never actually show a successful response from the core itself.
It turns out the issue is in /etc/ypserv.securenets for some odd reason my file had my external nic's IP as a trusted host, and none of my MD's nor the core's internal ip was listed as a trusted host. Adding
host 192.168.80.XX //MD's ip addr
for each configured MD and then doing a #sudo service nis restart allows the core and the MD's (reboot or run service nis restart on the MD's) to successfully bind to the NIS server and everything starts working great. ssh moonXX is basically instantaneous as you would expect from a lan machine. And even better the MD boot time is about 30-45 seconds from BIOS.
I haven't figured out what generates the ypserv.securenets file yet (I suspect its somewhere in one of the diskless setup scripts) but if anyone knows off the top of their head let me know.
Some things I will note.
My core was originally just designed to be a z-wave controller for lights/thermostat/etc... and not a media server. So the machine when I first installed LMCE had a single nic. Once I decided to put MD's in I added another nic and this caused issues with /etc/exports which I did resolve but I believe its possible that the same issues with the interface configuration were propagated into the NIS config.
Therefore if anyone else has had this binding issue and had 2 NIC's when they originally installed LMCE, please let me know so I can figure out if this was just a stupid mistake on my part for not following the guidelines and having 2 NICs in the first place, or if it is an issue in the diskless setup scripts.