On Fri, 17 Oct 2014 09:42:14 -0500 Colin Hudler <chudler@xxxxxxxxxxxxxxx> wrote: > We have a few hundred computers mounting an NFS server in a typical > LDAP-based users (nss) setup. We frequently add and remove exports and > use exportfs -r to update etab. Every time we do so, the clients report > "NFS server not responding" and start backing off their requests. After > a painful 3-5 minutes, they recover and life is normal again. > > We discovered that when the rpc.mountd cache flushing occurs, our NIS > system is overwhelmed with grouplist requests and this obviously blocks > things. We are working on that problem separately, and I admit this to > be a weakness in our setup. My question is simple. > > Why does it flush auth.unix.gid when the etab changed? I think it makes > unnecessary work for rpc.mountd because the gids are unlikely to have > changed, and they already have a reasonable expiration policy. > Most likely because no one really cared until now. When exports change, cache_flush() is called and that function flushes out all of the kernel caches. I expect that could be made to do something a bit more granular, but you may need to do some archaeology in mountd/exportfs (and the kernel) to ensure that you're not missing anything. -- Jeff Layton <jlayton@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
