Just...can't...get...it...to...work. So, I'm going to try XenServer free again and ask for help at the support forums for both Citrix and Unraid. I managed to get noac to populate into the NFS settings but lookupcache=none isn't taking. There are other settings in there and I'm wondering if they're getting in the way. I have to believe there's a way to make this work. From the nfsstat -m on the server:
/var/run/sr-mount/1804503a-ac43-f0eb-cd4a-18eff5098f21 from 192.168.169.8:/mnt/user/ISOs Flags: rw,sync,relatime,vers=3,rsize=131072,wsize=131072,namlen=255,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,soft,noac,proto=tcp,port=65535,timeo=133,retrans=0,sec=sys,mountport=65535,local_lock=none,addr=192.168.169.8