Sebastien Roy writes: > > 2) A dladm linkprop (read only) that shows the max MTU that is > > supported by the driver. The drivers will have to advertise this, > > which is a good thing - drivers should be advertising their > > capabilities in a consistent and standard way. MTU, speeds supported, > > any hardware checksum or offload capabilities, maybe even rings active > > and configurable. > > dladm already does both of these things (via the mtu link property). > The discussion is about going beyond that and providing some sort of > optimum values for this existing property.
To be more specific -- it's a performance thing. There are apparently a few drivers for which the largest allowable configured MTU is _not_ also the MTU that will result in the best application performance ... for some given definition of what "application" we're talking about and specifically what "performance" means in that context. (I suspect "application" means either NFS or iSCSI and "performance" means only "throughput," but that's just a guess.) Opinions on this are all over the map. Some think that not having best MTU == largest MTU is just plain a bug that should be fixed. Some think that it's an important inherent characteristic, but too fiddly to deal with from the CLI. Some think that it's absolutely crucial to system deployment and thus must be automated and cannot be dealt with by mere documentation. And there are probably valid opinions between those as well. Other than saying that some of the opinions seem to be given rather absolutely, I think it's hard to say what we've got for consensus. -- James Carlson, Solaris Networking <[email protected]> Sun Microsystems / 35 Network Drive 71.232W Vox +1 781 442 2084 MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677 _______________________________________________ networking-discuss mailing list [email protected]
