They are as safe as any other service provider. Ultimately, its always good practice to: 1. Do your own backups 2. Routinely test that you can recover from th

They are as safe as any other service provider. Ultimately, its always good practice to: 1. Do your own backups 2. Routinely test that you can recover from these backups I would argue that point (2) is much more important than point (1). I do try to do that at least once a month to ensure that there aren't any bugs in the backups, including any missing parts of the infrastructure. For mirroring really large data, rsync is a viable solution. Edit: I do want to add that performing your own backups is really subjective and you might need to ask yourself - what's the cost to me/my business/my users in the event that I can't recover from backups and or my provider failed in their own reliability (for e.g. Carbonite)