[LDM #TKJ-135497]: LDM Server Specifications

Hi Dan,

re:
> The Air Force Academy Meteorology Lab is planning on purchasing a
> dedicated system to run the LDM.  Can you provide some baseline
> specifications for a basic LDM server?  If I remember from last year's
> training workshop, system configuration will depend on the amount and
> type of data we bring in.  We hope to ingest surface obs, upper air,
> models (NAM and GFS), radar, and a limited amount of metsat data.

You are correct in remembering that the system configuration will
depend on what data you ingest, AND how much data you want to keep on disk.

When you say that you want to ingest NAM and GFS model output, are you
referring to the GFS model data that is in the NOAAPORT broadcast (i.e., in
the IDD HDS datastream), or are you referring to the GFS data that is
available in the IDD CONDUIT datastream or both?  The difference in volume
between the HDS feed and CONDUIT is very large:  in HDS you can expect on
the order of 195 - 375 MB/hour for all model data; in CONDUIT you can expect
on the order of 2.1 - 4.6 GB/hour of for all model data.  The volume numbers
for CONDUIT data are heavily dominated by GFS model output, so it would be
wise to plan on ingesting it when sizing a machine.

Given the above comments, it would be wise to purchase a machine with
the following characteristics:

- 64-bit, dual processors or a dual core processor of at least 3 Ghz
- 4 GB or more RAM
- 0.5 TB or more of hard disk

Machines like this can be purchased for $2500 - $3500 depending on discount
programs you can take advantage of since you are an educational institution.

Since you say that this machine would be dedicated to LDM use, you do not
have to be concerned with high-end graphics support... in fact, a machine
ingesting and processing the CONDUIT datastream is better configured to
_not_ run X Windows (X Windows uses a LOT of memory in current Linux
distributions). 

Other factors will come into play when sizing your machine.  For instance,
0.5 TB of disk may be more than you want/need, or it can be a lot less than
what you want/need depending on what you are trying to accomplish.  If your
objective is to keep a lot of data online at any time, you should think
carefully about purchasing an external RAID whose size is enough to store
the data you have in mind.  If you want to get going and not worry about
what storage capacity you need in the future, you should probably go with
about 0.5 TB.  Of course, an overriding consideration will be the amount of
money you have to spend and the deals that are offered by the vendor you
choose to work with.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: TKJ-135497
Department: Support Platforms
Priority: Normal
Status: Closed