As far as I can tell from a quick look the file is opened with fopen
and read with xdr. So unless the xdr implementation R is linked
against is doing something very weird, the input should be buffered.
On my RedHat 7.1 system strace output seems to suggest that the read
is buffered with a buffer size of 4096.
luke
On Fri, Jul 20, 2001 at 12:56:18PM -0400, Matthew Wiener
wrote:> Hi, all.
>
> I'm running R on a beowulf system, with software that can take a list
of
> single-processor jobs and parcel them out over the system. (In case
it's
> of interest, they're dual pentium 866 machines connected by fast
> ethernet.) The administrators of the system found that I was causing a
> huge load on the file server, and when they investigated it turned out
> that each process was reading in .RData 4 bytes at a time. Not kilobytes,
> bytes. The .RData in question is several megabytes, and more than one
> process is starting up at a time, so apparently it really adds up.
>
> I looked through the documentation, and a little bit in some of the
> source, and haven't been able to find how exactly .RData is read. Is
this
> part of the program? Is it something I can set? Is it something strange
> happening with the file system on the beowulf cluster?
>
> Any help appreciated.
>
> Matt Wiener
>
>
>
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--
Luke Tierney
University of Minnesota Phone: 612-625-7843
School of Statistics Fax: 612-624-8868
313 Ford Hall, 224 Church St. S.E. email: luke at stat.umn.edu
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