On Wed, 13 Oct 2010 10:26:25 -0600 "Mark Lehrer" <mark@xxxxxxx> wrote: > I have a few tgtd servers running and they are doing very well. I would > like to add a 2nd server as a backup so I have one question. Assuming that > the block device mirroring and IP/Mac failover are perfect ( kind of like > assuming a frictionless surface in physics :) ), how well does stgt fail > over to a 2nd server? I think that there are people that use such configuration. > The simplest would be for the clients to reconnect to the new server and > re-establish communications. However, how painful would it be for the new > server to keep the same sockets open for a truly seamless failover? Again, I don't think it matters. The simplest solution (multipath) works well for lots of people. Sharing the state between two hosts is too complicated. > I am only concerned about the tgtd internal states at this point - assume > that the block device mirroring as well as the > keepalived/heartbeat/iptables/fencing/etc issues are handled already (though > there would obviously be a good bit of integration work there!). > > My 2nd question - I am starting to play with things like ionice and > scalability. One critical aspect of scalability is limiting the first > connection's performance so it doesn't degrade so quickly as more clients > come online. It appears that ionice will probably not have the features I > need; is this on the tgtd roadmap? Even something as basic as a generic "io > operations per second" would be a good start. We've just aded the feature to get such stats. -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
