Performance statistics aggregation

[Mark Seger]

> I've always liked sysstat for this, as its almost totally invisible
> in terms of system load but has a wealth of information for diagnosing
> chronic problems. As was pointed out elsewhere, this doesn't show you the
> brief spikes, but getting those involves a lot more data collection. :-P

are you aware just how light-weigh frequent collection is?  collectl does 10 
second samples of maybe twice as much data as sar plus 1 minute samples of all
process and slab data.  uses about 0.1% of the cpu and even less if you leave 
off the process/slab data.  and collectl is written in perl!  Just think how 
much more  efficiently sar could do it.  but then you'd lose the benefit of all 
collectl's additional features.  ;)

> So if a customer is taken on, then installing something like sysstat
> should be one of the first recommendations.

but only if you take 10 second samples.  otherwise install/start collect which 
is already configured at that sampling rate by default.

> Of course, there's also Landscape, if you're so inclined to hand over
> a little cash, you get a lot of this built in (and a lot more ;)

re rdd, which was mentioned in an earlier note.  I tried loading collectl data 
into rrd and as soon as I found the plots are not accurate, I stopped using it.  
stick with gnuplot like colplot does.

-mark