qmailtoaster-list  

[qmailtoaster] Virtual QMT

Phil Leinhauser
Tue, 09 Feb 2010 09:39:33 -0800


Sorry 'bout that.  Never used threaded view...

So, I
restarted this one and added below...

Sorry, Phil. I posted reply to Jake before I read this.

BTW, when you change a thread, please create a new message (copy/paste

content as appropriate) instead of replying and changing the
subject. 
When you look at messages in threaded view (nice feature
btw), this 
isn't a new thread, only a changed subject. :( Common
mistake.

Phil Leinhauser wrote:
>
So let's change the thread and explore yours a bit...
> 
> I'd be
interested in where virtual QMTs choke.  Is it IO, proc, mem?  
> Maybe too many other guests?
> 
> While
I only have about 1/2 of your 500 user choke point, I get very 
> good performance from my VM server based QMT.
 I did have issues before 
> I found
some of the tuning points that I'm documenting in the wiki.  
> I've been running some sort of VM in my small
business since the days of 
> GSX and
in work I have a very large install of ESX / vSphere.  I do know

> things like heavily used databases
and the like don't run too well 
>
virtualized.  I'd be interested to see if the QMT limit is something

> that can be overcome?

Me too. I think/feel/hope there's a way to improve on that.

FWIW, I talked with a company a year or so ago that was running
Oracle 
in virtual guests, and they had managed to obtain
satisfactory 
performance. They didn't go into specifics, so I don't
know how they did 
it. Can be done though I believe.

> I saw your discussion a few days ago with Eric about
slow virtual 
> performance but you
said that was with something other than VM?

> That
was one Xen server. I don't know about the others he was working on 
> though.

We did have a couple Oracle databases on our ESX
3.5 but they seemed to choke. 
I was in the middle of building the
infrastructure so I couldn't help him (Not that I would have been much
help with Oracle).

Is there anything like a load tester for QMT
to mimic the 500 user limit?