"Hey, you know that background image we've been using for 5 years for the X site? Where'd we get that? iStockphoto? Can you track down the purchase info along with proof that the $3 was for *that* photo? I think that was a few years before Getty bought them, and I think we were still Y Corporation at the time. Man, I sure hope Jimmy didn't just do that on his own account for convenience. Any idea where he is these days?"
Heck, I was at someone's office today where they couldn't find the paperwork for an out-of-warranty laptop repair from March, much less something years old.
Also a couple of less business-oriented systems from Lenovo (based on their on-site search looking at 1600x900 and higher on screens of 13 or 14 inches): Their Flex2 14, this week's "deal" at $699 with a 4th-generation i7 and 1920x1080, which makes me go "wow". I'm going to include the link because that's pretty impressive: http://shop.lenovo.com/us/en/laptops/lenovo/flex-series/flex-2-14/?sb=:000001C9:00011EDA:
They also have one of their Yoga 2 systems, 13" also 1920x1080 with 4th-gen i5 for $900.
And of course you can get higher resolution even cheaper if you're looking at giant 17" screens.
Admittedly in this case there aren't any major differences in functionality, and we may end up with the Russian one after all if testing shows its interface is easier to use/train on, but it's the first time I recall actually looking into and considering where the software is being created.
The first is to have your own offsite storage that you back up to, where the backup is (at least) as large as the original. Multiple people have recommended Crashplan, and that's certainly a viable option. There are undoubtedly other options that could do similar things depending on how down into the weeds you want to get - rsync, the various rsync-based versioning backup solutions, git-annex as mentioned by someone else though that one's new to me. I'll note that from experience with Crashplan's Enterprise product on some older 32-bit servers, the client software can chew some fairly significant memory when you have a lot of files or data.
The other and probably simpler option is that when you start to near capacity on the storage system, don't upgrade it - shut it down and store it, preferably not in the same (not-yet-burning) building after building the new system and copying the data over to it. After you shut the old one down, keep backups of anything you've changed since that "checkpoint" system; hopefully your data isn't changing that rapidly - 20 TB seems to me almost guaranteed to be mostly static.
If you do need the paid version, Tacit Dynamics (tacit.dk) apparently has it available through Amazon.com and through AndroidPit.com as well if either of those will work for you. The drawback of either is that I believe (as with most competing app markets) you have to keep that app market installed on your device.
If that doesn't do the trick, I find that my tablet running Cyanogenmod 10.1.3 has rsync 3.0.7, but I've also installed extra bits and pieces ("Android Terminal Emulator" by Jack Palevich, "Terminal IDE" by Spartacus Rex, "Busybox Pro" by Stephen (stericson)) so I'm not 100% sure that it was originally available. You may be able to script and schedule something of your own based on scripts you use elsewhere, though with a few changes (e.g. "jping" instead of "ping", see Issue 29 on Terminal IDE's code.google.com page though that indicates that it may be fixed).
There's also a "lite" version, which only allows 2 accounts, no Tasker support and no sync filters (which I've never fiddled with anyway, so may not be that important).