The problem isn't with the RPC - its with the additional disk writes. The single lrgest metadata performance gain we achieved was by changing the atime_diff parameter in /proc
Brian J. Murrell wrote: > On Tue, 2008-04-29 at 13:09 -0600, Lundgren, Andrew wrote: > >> I don't need to know the last access time on my files. I looked >> though the manual, but didn't find a reference to noatime. Does >> lustre use that setting? (on the cl >> >> -- >> >> Adam Cassar >> ICT Manager >> NetRegistry >> ------------------------------------------------------- >> o: 02 9699 6099 >> f: 02 9699 6088 >> d: 02 9641 8609 >> ------------------------------------------------------- >> >> Netregistry Pty Ltd >> www.netregistry.com.au >> PO Box 270 Broadway, NSW 2007 >> tel: +61 2 9699 6099 fax: +61 2 9699 608 >> ient and/or server) >> > > I don't believe it does because... > > >> On a file system that is read heavily, I would expect to see a >> performance improvement by using that. Is that true for lustre as >> well? >> > > Lustre already handles atime in a pretty efficient manner. Rather than > disable it completely we update it "lazily". What that means is that > rather than sending immediate and explicit RPCs to update the atime we > will delay sending them (for up to 5 seconds, tunable IIRC) and try to > send atime updates "piggybacked" with other RPC traffic. > > b. > > > ------------------------------------------------------------------------ > > _______________________________________________ > Lustre-discuss mailing list > [email protected] > http://lists.lustre.org/mailman/listinfo/lustre-discuss > -- Adam Cassar ICT Manager NetRegistry ------------------------------------------------------- o: 02 9699 6099 f: 02 9699 6088 d: 02 9641 8609 ------------------------------------------------------- Netregistry Pty Ltd www.netregistry.com.au PO Box 270 Broadway, NSW 2007 tel: +61 2 9699 6099 fax: +61 2 9699 608 _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
