On Thursday 20 March 2008 01:15:04 pm Mark Seger wrote: > not sure if you're talking about collectl
Not I wasn't, I was referring to the Lustre Monitoring Tool (LMT) from LLNL. > Be careful here. You can certain stick some data into an rrd but > certainly not all of it, especially if you want to collect a lot of > it at a reasonable frequency. If you want accurate detail plots, > you've gotta go to the data stored on each separate system. I just > don't see any way around this, at least not yet... Yes, you're absolutely right. Given its intrinsic multi-scale nature, a RRD is well suited for keeping historical data on large time scales. This could allow a very convenient graphical overview of the different system metrics, but would be pointless for debugging purposes, where you do need fine-grained data. That's where collectl is the most useful for me. But what about both? I don't see any reason why collectl couldn't provide high-frequency accurate data to diagnose problems locally, and at the same time allow to aggregate less precise values in RRD for global visualization of multi-hosts systems. > As a final note, I've put together a tutorial on using collectl in a > lustre environment and have upload a preliminary copy at > http://collectl.sourceforge.net/Tutorial-Lustre.html in case anyone > wants to preview it before I link it into the documentation. > If nothing else, look at my very last example where I show what you > can see by monitoring lustre at the same time as your network > interface. Very good, thanks for this. The readahead experiment is insightful. > Did I also mention that collectl is probably one of the few tools > that can monitor your Infiniband traffic as well? That's why it rocks. :) Now the only thing which still make me want to use other monitoring software is the ability to get a global view. Centralized data collection and easy graphing (RRD feeding) are still what I need most of the time. Cheers, -- Kilian _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
