On my Linux system, when I encounter too much swapping, I can reduce that by resetting "swappiness". For example, to see what the system default is:

sysctl vm.swappiness
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On my system the default is 60. I have 512mb ram. So if i want to retrieve a file that is 4G, then I would reset swappiness to 0 to speed things up. To reset, just:

sysctl -w vm.swappiness=0
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After the retrieval is finished, reset back to default.