In response to "Anders Boström" <[EMAIL PROTECTED]>: > >>>>> "AL" == Arno Lehmann <[EMAIL PROTECTED]> writes: > > AL> Still the network is being used and that always involves latencies, > AL> syncronization times, etc. > >> > >> Yes, and that might be the problem. But if it is about latencies > >> and/or synchronization, then it is a bacula performance problem! > > AL> No, what I'm talking about is network fundamentals. Whenever you send > AL> data across a network that takes time, and it takes more time than > AL> dividing xMBit/s by the amount of data. Always. > > Are you talking about the long-fat-pipe problem? This isn't an issue > for us... Linux has a very good TCP-implementation, with > window-scaling, and we are running over a local GE-network with less > than 50us latency.
It's not the LFP problem. First off, every TCP packet adds overhead to your data, which means 1G/sec is really only about 600mb/sec in practical measurements. Secondly, that's 50us per packet. Which means there's work to be done on both ends to normalize packet flow, ack, retransmit lossed packets, etc. I believe someone asked you to double-check that all speeds and duplexes are matched, as that's a _very_ common problem (especially, in my experience, with gig HW). If you responded, I missed it, but I recommend that you double-check. However, also read on ... > >> Is bacula limited in performance due to high latency? (Not that we > >> have that problem, but anyway...) > >> > >> Is bacula limited in performance due to synchronization? > > AL> Networks are limited by several factors. That's not something you can > AL> fix, and network throughput is not normally the most limiting factor in > AL> a Bacula setup. > > The specific issue here is about bacula. Has bacula any specific > limitations regarding the network? Please be specific, and don't just > generalize. Well, we're off on the wrong foot, in my opinion. There's no indication anywhere that networking is a problem. You even said that you were seeing indications in network traces that network traffic was flowing fine. As a result, I'm a bit confused as to why there's so much focus on the network, but I expect it's a result of the _huge_ number of people who assume that everything is fine with the network, then blame the application, only to later find out that there's something seriously hosed with their network. I've fallen into that trap, but I don't think you have in this case. I'm going to address what I _think_ is the problem in a response to your other email ... -- Bill Moran Collaborative Fusion Inc. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
