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2011/5/17 Lukasz Janyst <[log in to unmask]>:
>   Yes, this is quite correct. You can do similar adjustment with
> XRootD. Unfortunately in the older versions (coming with ROOT<5.28)
> you can do that only by putting a .rootrc file in the CWD of the job
> that you're running or in $ROOTSYS/etc, in versions coming with ROOT
>>5.28 you can set it via envvars.
>
>   You can have three values for ReadAheadStrategy:
>
> 0) no read ahead
> 1) sequential - read some data ahead of currently requested buffer
> (how much should be read is specified by ReadAheadSize)
> 2) sliding window - window centered on the recent average slides
> through the file following the stream of the requests
>
>   ReadCacheSize denotes how much data should be cached per file.

I forgot to add that you can also play with a number of parallel
streams, which should speed things up for WAN usage.

   Lukasz