What's the cloud solution (at major providers) that automatically geographically replicates data? For example, S3 buckets are tied to a region, which cannot be considered reliable - a single DC can always burn down, or even just intermittently unreachable. I'm looking for something that accepts an "upload" command that will (eventually) replicate the data to several regions. Ideally the regions can be changed at any point later, too.
This would take care of 3 and 1, sadly not 2 but 2 is pretty hard.
A region for AWS or GCP (and surely Azure) is more than one physical data center. A given data center (availability zone) can fail with no data loss. You have to choose very specific storage tiers with warnings galore to get to a point where one data center will cause data loss.
There is also multi region buckets which go across regions.
I use RClone and Duplicacy to backup to S3 Glacier and Google Workspace. Kopia is also another up and comer.
For a simple copy type setup RClone is a good one to look at, by default it copies the files and doesn't do any snapshots, packing, splitting, etc.
S3 offers multi-region buckets that automatically read/write from one of n buckets in n regions. Cross-region replication rules give you eventual consistency (without conflict resolution) across all buckets, which is good enough for backup systems with unique file names/paths.
I can't find the article anymore, but a few weeks ago here on HN there was a piece where somebody did a few calculations on how AWS US-East-1 (the most used AWS region in the world) works, and got to the conclusion that all the things that can make that region go BOOM are likely to have major consequences to our civilization.
In short: AWS will go down only when you won't care about it anyway
This would take care of 3 and 1, sadly not 2 but 2 is pretty hard.