Am I at risk of data loss if I have multiple Linodes hosted within the same datacenter?

This is a great question!

When you create a new Linode, it is distributed to a host within your chosen datacenter based on availability. That being the case, it's very unlikely that multiple Linodes would end up residing on the same host -- it's more unlikely still that multiple hosts within the same datacenter would go down concurrently. On top of this, you can check which host your Linodes reside on at any time from your end -- if you notice multiple Linodes on the same host, you can absolutely request that the Linodes be transferred via Support ticket.

The first step you can take to avoid data loss is to create a highly available setup. We actually have a great guide in the Linode Library that explains how to configure such a setup -- we'd recommend taking a look.

As unlikely as it is for multiple hosts within the same datacenter to go down simultaneously, it is technically possible for a datacenter to suffer from a catastrophic incident. If you're concerned about this, you may want to create Linodes in different datacenters and configure IP failover in the event that such an event occurs. We have another guide that explains how you might go about this as well.

Lastly, it's worth noting that backups are stored on hardware separate from Linode instances themselves -- these backups can be restored to any Linode located within the same datacenter.