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Re: who's "Mr/s LDM" these days over there

Karl Hanzel wrote:
> 
> 
> Thanks for your comments Anne & Jeff!
> 
> We do still decode on ours (i think).  Dunno how big our queue is.
> Tim?
> 

A more telling bit of info would be how many hours worth of data is in
your queue.  To find this out, do 'pqmon'.  The last column is the age
of the oldest product in the queue in seconds.  This can help you decide
if the current queue size meets your needs.

Most of our sites run with a 2GB queue or less.  (Some run with just
500MB.)  But, like Jeff said, we're currently running with a 7GB queue
on our main server.  We had to go bigger than a 2GB queue in order to
keep a minimum of one hour's worth of data at all times. (7GB gives us
anywhere from aoubt 2.5 to 6GB in the queue, depending on the time of
day.)  Building a queue larger than 2GB requires large file support,
something to keep in mind if you want to keep a lot of data in the
queue.

RAM is definately a place to spend some money because, as Jeff said, the
more of the queue you can keep in memory the better.

If you're going to be decoding a lot, then a fast disk is also
beneficial.


> Any pointers on the latest Sun/x86 news?  This could be a factor in the
> decision if there was a good chance they're dropping it.
> 

Here's one article: 
http://www.infoworld.com/articles/hn/xml/02/04/19/020419hnsecretsix.xml?0419. 
It appears that the jury is still out on this decision.  At the very
least they said they'd continue to support it for the next seven years,
so that may be long enough for you.

> If so, do you guys have a favorite cost-performing Sun/Sparc box?  Our
> present LDM machine is a 2-cpu Sparc-II... i think it clocks at 300 MHz,
> but i'm pretty sure we only have 1 GB of RAM, and maybe that's slim(?).
> It always seems to be pretty busy/bogged.  Or maybe that's just relative
> to other hosts we have, and i should think of it as being "pleasantly
> busy"(?).
> 

1GB of RAM would get you by with a 2GB queue, especially if you're not
trying to feed a bunch of other hosts or doing much decoding. 

We tend not to buy low end machines, which I assume is what you're
looking for.  The SPARC stations on some of my coworkers desks cost
about $12K.  But, probably any low end SPARC would serve.

> Our motivation for upgrading mostly involves attaching an LVD tape
> library (no LVD SBUS was/will-be available), and getting something that
> does Gig-e.
> 

Why do you want Gig-e?  I was talking to Mike about this - our main
server, thelma, which may be the busiest host in the entire IDD, has
never gone over 100 megabits.  And, he says those gig ethernet cards are
pricey. 

Anne 
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Anne Wilson                     UCAR Unidata Program            
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