Comment Re:Crashplan may be affordable (Score 1) 983
Ive used Crashplan for years at clients, friends, and personally, and its generally been good. They have 2 options that may work here.
The first is their all-you-can eat backup service, but they may well balk when you tell them its 20TB-- they might shove you to a $120/year business plan.
The other is buying a pack of Crashplan ProE licenses, which let you host your own cloud backup service. You can use any PC as the "server" (just make sure its reliable and on 24/7) and it handles diffs like a champ. It also verifies backups to avoid bit rot.
You can use the free version. Setup another computer with sufficient capacity, so probably 6x 4TB external drives in a ZFS system of something like that. Make the first backup locally. Then move the computer to another location.
Only catch with these local backups - it seems to be that when CP goes offline (bankrupt), even the local backups won't work anymore. Just disconnect the network cable from the backup server, and then try to restore a file from the local backup to test this. I use CP myself, and haven't seen anything that compares in price, but this "feature" is something I really don't like.