Re: Question about addfile command

In my view, it is the nfs mount

On two systems

I used the following on **hard wired local disk subsystems**

==================================
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
wcStrt = systemfunc("date")
f = addfile("ei_oper_an_sfc_15x15_90N0E90S3585E_20000612_20010117.grb","r")
wallClockElapseTime(wcStrt, "addfile" , 0)

wcStrt = systemfunc("date")
x = f->CI_GDS0_SFC
wallClockElapseTime(wcStrt, "read variable" , 0)

print(f)
===================================

(0)
=====> Wall Clock Elapsed Time: addfile: 0 seconds <=====

(0)
=====> Wall Clock Elapsed Time: read variable: 1 seconds <=====

Variable: f (file variable)

filename: ei_oper_an_sfc_15x15_90N0E90S3585E_20000612_20010117
path: /tmp/ei_oper_an_sfc_15x15_90N0E90S3585E_20000612_20010117
    file global attributes:
    dimensions:
       initial_time0_hours = 880
       g0_lat_1 = 121
       g0_lon_2 = 240
    variables:
       float CI_GDS0_SFC ( initial_time0_hours, g0_lat_1, g0_lon_2 )
          center : European Center for Medium-Range Weather
Forecasts (RSMC)
          long_name : Sea-ice cover
          units : (0 - 1)
          _FillValue : 1e+20
          level_indicator : 1
          gds_grid_type : 0
          parameter_table_version : 128
          parameter_number : 31
          forecast_time : 0
          forecast_time_units : hours
[SNIP]

On 12/08/2010 08:47 PM, Gareth Berry wrote:
> Hello!
>
> I have a quick question about the addfile command: I've been reading
> some large (1.7Gb) grib files in a plotting script and it's become
> apparent that the addfile command is taking an outstandingly long time
> to execute. I'm curious as to whether they is a way to speed up the
> process of opening a grib file?
>
> I'm using files from a local server via an nfs mount - from my network
> traffic I noticed that ncl transfers an amount of data about equal in
> size to the file itself. I would of assumed that addfile would not
> transfer this amount of data. I'm using ncl 5.2.1 on MacOSx 5.8, but
> have experienced the same issues with ncl 5.1.1. I don't think the nfs
> mount is the culprit as the long wait is not reduced significantly if
> I run using a file stored on my machine (both take ~1 min to read 1.7
> Gb). Any help or suggestions are most welcome!
>
> Cheers,
>
> Gareth.
> _______________________________________________
> ncl-talk mailing list
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk

-- 
======================================================
Dennis J. Shea                  tel: 303-497-1361    |
P.O. Box 3000                   fax: 303-497-1333    |
Climate Analysis Section                             |
Climate & Global Dynamics Div.                       |
National Center for Atmospheric Research             |
Boulder, CO  80307                                   |
USA                        email: shea 'at' ucar.edu |
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