Peter Tribble writes: > It's probably fair to say that sar is heavily used in some > organizations (and less so in others). We collect it anyway, so I've > been doing some data gathering based on it, which exposes some of its > limitations: > > 1. No networking. This is an absolute killer. The concept of > networking seems to have been somewhat, ahem, neglected.
I just have to ask, have you looked into statistics collectors like Munin? http://www.munin-monitoring.org (disclaimer: my company does the main development on Munin) > What if we just scrapped the current sar collector (sadc) and just > saved kstat -p output (or something like it) instead? Munin wouldn't be a replacement for that, the plugins are pretty hardcoded in what is graphed, although they are easy to extend. > Is this practical? How big is the data? > > On one of my machines, a thor, a regular sar datapoint is about 64k. > The kstat -p output is about a meg, but zip gets that down to 160k, and > 7z does significantly better. On a T5140, the sar data is about 20k and > kstat about 2 meg, so there the difference is much larger. But I feel the > idea has promise - in the best case we're almost there already, without > optimizing the saved format or trimming unnecessary data. on a random machine of mine, I got 980k raw and 137k compressed (gzip -9). collecting this data every 5 minutes from, say, a medium-sized installation of a hundred hosts, you need 4 GB storage per day or 1.4 TB per year. I think that is impractically large. Munin, Orca, Cacti all use RRD to consolidate data, so that sample rate decreases with age. would it be possible to do the same with kstat output? my guess is that it is difficult without knowing a priori what kind of value we're consolidating (is it a counter or a rate?). many values are neither, complicating a general collector further. -- Kjetil T. Homme Redpill Linpro AS - Changing the game _______________________________________________ sysadmin-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/sysadmin-discuss
