Folks, I have just been informed about something that we have been discussing recently on toasters. The issue was exports allowing NIS netgroups to be used in the rw= and root= options on the exports of file systems. The above RFE was posted
7 YEARS AGOThe reason for not allowing this was sited as performance issues. Well, we have come an awful long way with speed and abilities in this time. I think it is just plain silly that this RFE has been ignored for so long. Solaris allows this now and I don't think the issue will be resolved until enough people complain.
I wonder how Solaris does it.
It's my understanding that the access= list is consulted at the time of the mount. It's OK to take the time to look up a host in a netgroup at mount time.
I think the rw= and root= information has to be checked for each NFS request. So that is the performance issue. I know for a fact that you can change the root= info on the NFS server, exportfs again, and the change happens on all NFS clients without having to umount and mount the volume again. In other words, on the NFS server you can unilaterally grant or remove root= access for actively mounted NFS clients.
If these privileges were set at mount time, then you would have to unmount and mount again on NFS clients in order for the change to take effect.
I suppose the NFS server could cache the rw= and root= information for recently active NFS clients to avoid most netgroup queries.
Steve Losen scl@virginia.edu phone: 434-924-0640
University of Virginia ITC Unix Support