A customer had their DVR suddenly delete all 200 recordings that were stored. Is there a way to back up the recordings to an external location?

Yea, you can plug a USB storage device in the back and format the drive then transfer them to the external device, they used to have a document that would step you through it on their website under the support tab. If you can't find it let me know and I will try to locate it when I'm back at the office for you.

Yes, but there are some caveats:

limited to 1 or 2 Terabytes (I forget) and HAS to be a single platter drive. AND self powered- not USB bus powered.

It's also a SLOOOOW process. I recommend "sending to External HD" only 3-4 shows at a time. If you try more than that, they sometimes bog down.
It does work though, I've "saved" way too many cartoons for my daughter, and a few select shows that I wanted.

I recommend doing it occasionally anyway for long term keeper shows as HDs fail all the time in consumer devices (especially ones that they {sat/cable providers} can give out for free by the millions...)

Can it auto backup? Or do you have to do it manually?

Manually.

Also, once transferred over to the external drive. The client can not view it via Sling Box, or whatever Dish calls it. So they can't watch the transfer DVR event on their iPad, computer or whatever. Unless they transfer it back to the receiver. At least this is true on the Hopper. I could swear I could with my previous 722k system, but I can't remember.

I have 1TB from Seagate. P/n 9SF2A4-500. It has events on there from both my 722k and Hopper. And the Hopper sees both and transferred to/fro with no problems. Of course, as mentioned, don't do too much at al time.

I've done 20 to 30 and it took 24 hours. At the end, it gave me a failed message. But all events were transferred. Will I trust doing that with a clients? Probably not.

KOT