Thank you for your quick replies -- The files are roughly 1kb-1mb, average is 10kb. 300 bytes per file is fine as long as it doesn't need to hold them all in memory at once? Does it should move through the list of files one by one? 300 bytes * 100M files is 30GB of ram needed :\ I don't mind if the initial sync takes a few days, but I add to the "master" server every day with 200mb of files, which I hopefully want sync'd to all the slaves within 2-3 hours. Thank you for your help, Best