[csw-maintainers] [csw-buildfarm] BO Buildfarm available again

[James Lee]

On 14/01/10, 21:43:09, Dagobert Michelsen <dam at opencsw.org> wrote regarding
Re: [csw-maintainers] [csw-buildfarm] BO Buildfarm available again:

> >>>> The T5220 is now split into two LDoms: One LDom with the existing
> >>>> Solaris 10
> >>>> instance carrying all of the Sparc stuff which was already there
> >>>> (now
> >>>> restricted to 12 GB Ram and 20 Strands) and one LDom with
> >>>> OpenSolaris
> >>>> 06/09 Sparc still installing with 3 GB Ram and 8 Strands.
> >>>
> >>> Any reason for the restriction?
> >
> >> Because the machine doesn't have more resources ;-)
> >
> > Excuse me the machine does, prior to enhancement each virtual machine
> > had 60% more available CPUs.

> Is this a problem for you?  Are you really using that many parallel
> threads?

Yes, but only at times.  OpenOffice.org is the worst and uses all
threads for long periods (when the disc isn't dying).  Looking at my
current terminal output tiff says "build8s --> 20 jobs" several times
but not for long as the whole build only takes 6 mins for everything.

Problem is the wrong word.  Only recently has the build farm had enough
disc space and I've built OOo on my own Pentium 2 333MHz, it took 4
days not 6 hours but did get there.  So it's not a problem but more
is better, 5 minutes is better than 6 minutes and it won't be too fast
until it's quicker than pressing a key.



> > Ah yes so LDOMs are restrictive.  Sorry I've only read the marketing
> > bumph which suggests resources are shared.

> Yes, the machine is shared like "there are two OS instances on shared
> hardware". The hardware is not shared, but partitioned.

> > That is on the misleading
> > side of truthful as there is no dynamic sharing of CPU and memory.
> > Where load is sporadic as for build hard partitioning is a waste of a
> > good machine.

> I had the impression that the T5220 wasn't used that much at all. Most
> of the time the load is beneath 3 or 4

Exactly the problem I mean by sporadic load.  Something like a busy email
server will have a continual somewhat random stream of messages and will
have a meaningful average load.  A build the machine is idle until it's
used, then it's busy.  The load average means little, being low means no
one is working.  You should only take the load average of when it's busy
which sounds silly but is right because the load when no one is using the
machine doesn't matter.  This is where average isn't important, as with
the average number of legs on people, or rating the fire brigade by the
percentage of time they are actually putting out fires.


If it's a natural consequence of using LDoms then so be it.  It's a
shame they can't dynamically share threads, as with unrestricted zones,
because for very uneven loads it's what is needed.



James.