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