On Sat, 13 Jul 2019 14:03:44 -0500, Charlie Hoffpauir
wrote:

Now assuming it IS important, how do you back it up now? I have only a
couple of TB of data that I can't afford to lose, and I back it up
with triple redundancy... to a removable hard drive every 5 days, and
to an always on-line NAS unit daily. I really can't imagine how I'd
back up 50 TB of data. But however you do it, why not simply connect
your backup system to the new computer and transfer the after backing
it up from the old computer?

I've more but similar. Some magnitudes larger than your 2T but some
magnitude smaller than 50T.

It's very obvious, a priori: On The Cheap.

First, scrap the triple-redundancy;- Double is efficient for
adaptability to an order of a Tower of Hanoi redundancy scheme at
penta, for 5-day, business workloads. IOW - How to ensure the last
backup is maintained for integrity at a current state of operable and
employed HDDs. Which means software, and not necessarily an
uncomplicated software scheme.

Back to cheap, one backup, then. That is, obviously, SATA which
everybody everywhere has. Hot-swapping would be nice to near
essential at an heavier schedule for regular maintenance on back-up
loads;- Hot-swapping as integral to both BIOS and OS support. How
that is to be obtained is no less obvious: A cheap external docking
bay, containing one or two drive slots;- commiserate to ESATA ports
and/or SATA3 speeds, USB2 will be unacceptable for 50T.

So, here we are with, effectively, no money invested and an actual
solution, one of course within limitations. A ESATA port, off the MB
and backplane of the case, or USB3 for nothing, already given the MB;-
Docking stations aren't much either. Add to that a tiny 3"- or 4"-fan
115V fan, to plug in and keep the external drives(s) cool enough not
to burn out.

Within both limitations operational characteristics across a relative
acceptability to time. A 2T copy operation, then, will occur perhaps
over five hours;- 15T over the course of a week, and 50T during that
month.

Thus small-time operations for small-fry operators running 50T for no
cost other than buying 50T worth of HDDs.

How far is that from an enterprise solution with no bottom line on the
cost of the latest and fastest equipment? I'd guess 50T, for 25T
backed-up and copied 25T (at not realtime redundancy RAID operations),
anywhere from a day to 72 hours three days. For a state of the art
business server solution with 25T data storage considerations;-
network category cable carriers, of course, which may practically be
something slower than current MB controller technology and SSDs.

Such as may cost, in the later instance, conservatively to estimate a
build at optimized a 50T for $20K, as opposed to a rather large plank
of wood for placement of a home PC build with perhaps $2T to invest in
50T of HDD units for something a tenth slower.