Not always an option. For instance, I use Linode’s backup service and it can only back up to the same data center (although it is said to live on a separate system).
You can, and should, back up your irreplaceable data elsewhere using a custom solution. Unless it's some service that doesn't allow you to export the data at all, it may be inconvenient, but it is an option.
Coming from a Linode employee, I can confirm this is true. Linode's backups live in the same data center as the server, but the systems are separated so that they don't directly affect one another.
Do they have separate power supplies? Have steps been taken to ensure that fire can’t spread from one room to the next? What would happen if there was an explosion?
In all seriousness, these are good points. I'm not a data center expert by any means, but here's what I know: The data center hardware has failsafes present by design, but they aren't disaster-proof being that they're in the same building.
To answer your questions: Yes, the backup storage box is in a separate chassis than the host machine that the Linode lives on; they have separate power supplies. The DCs themselves also have some sort of fire suppression. I don't know what would happen if there was an explosion.
They could mean using regular data transfer (i.e. using something like rsync instead of the provider's backup service). Maybe egress costs among servers from the same provider are reduced or nullified.
From[1]:
> Traffic over the private network does not count against your monthly quota.
I wonder how private addresses are setup by Linode.
Each data center has an internal private network with a pool of private IPs available for assignment. If a private IP is assigned to a server, it then has access to the private network.
