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Use cp -r -p -v to preserve the mode, ownership and timestamps, recursively copy directories and explain what is being done.
Since this will take a lot of time (day or so) you may want to try cp -r -p -v <from> <to> >! log& and use top and tail log to watch progress
Use rm -r -v to remove files that have been copied from /nfs/slac/g/net/pinger/pingerreports/new/
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