First post, hope it helps someone else storing large amounts of data online.
I use a cloud service, Bitcasa (NOT recommended) to serve my media library and for personal backup. They've recently radically changed their business model, and given a 3 week notice of a 12x price increase part way in to a year long subscription on beta customers like myself who've been helping as paying customers for several years while they iterate their product. All this to say I recommend staying away from them. I've had it, will never trust them after breach of contract, so I'm in a rush trying to download and verify over 7TB of data.
Having already downloaded 7TB from Bitcasa, it appears some is corrupted. It's not clear whether the original data was compromised in original transfer, or in their database servers, or errors occurred in download. Courts ordered an extension to Nov 20th for customers to DL data, however I don't have long before the data must be DLed before the Bitcasa service change. Most of the data is DLed, but I don't have confidence in the transfer.
In short, what's a good, fast, and reliable software/service to verify TBs of online data against my downloaded copy in a Mac Yosemite environment? My ISP has at best a 100/10 transfer rate. I'm not afraid of command line. File count is likely in the hundreds of thousands, mix of large and small, .txt to GB size media. Given time constraints, the verification should be multithreaded if possible. Any suggestions welcome!