[Xymon] FreeBSD Actual Memory Usage

[Mark Felder]

On Thu, Nov 21, 2013, at 0:23, Jeremy Laidman wrote:
> Good Xymon Folks
> 
> Xymon doesn't support reporting "actual" memory usage for FreeBSD systems
> -
> 

Correct, and this is quite annoying!

> 3. I could report each of the different memory metrics separately to
> Xymon:
> active, inactive, wired, cache, buffers, free.  Then I can graph them
> all,
> and look for various conditions on each of them separately, or in certain
> combinations that make sense.  This is the most flexible option, and
> would
> provide the highest degree of insight to someone trying to troubleshoot a
> sluggish server, but it requires a lot more work on both client and
> server.
>  It's also specific to *BSD systems.
> 

Yes, more data is better. For example, look at what Observium pulls over
SNMP vs what Xymon reports:

http://imgur.com/a/P4Qq1


> So, any other suggestions on the best way to achieve this?  Which of the
> above is the best approach, do you think?
> 
> The other issue I have is that nobody seems to agree on what's a useful
> measure to keep an eye on.  The Xymon server-side code for Darwin reports
> used memory as the sum of active, inactive and wired.  But other sources
> use the sum of active, wired, cache and buffers.  Yet other sources say
> that buffers cannot be freed, and also that inactive pages are kind-of
> available if needed.  My intention is to be able to predict when it's
> time
> to add RAM to avoid performance degradation, but it's not clear what
> numbers are going to give me that.
> 

Graph it all as granularly as you can. Let the admins figure out what's
important to monitor.