Using Windows Azure storage for backup
You would probably be better off using the Azure Online Backup service rather than trying to roll your own. There is an agent that you install on each computer and it integrates with the Windows backup console.
http://www.windowsazure.com/en-us/services/backup/
To answer your questions about Azure Online Backup:
There is an agent
This depends on your internet connection, not Microsoft's
It transfers over SSL, if that's what you mean. "Is it secure" isn't really a question, since it means different things to different people.
Good answer by @MDMarra. Providing one other perspective, to round out the answer: You could roll your own backup, using Blob storage as your backup storage medium. You're right that there's a REST API, and there are also SDK wrappers for .net, Java, php, python, ruby, and node.js, as well as both PowerShell and node-based cross-platform CLI, all capable of manipulating storage.
Regarding Robocopy: Because blob storage has a REST-based protocol underneath, you'd need a tool slightly different. The Azure team published AzCopy to provide functionality very similar to Robocopy.
So... in theory you can create your own backup/restore scheme. This will have a cost footprint equivalent to the cost of Storage only. However: As @MDMarra pointed out, the Azure Backup Service provides a backup service, which is richer feature-wise than just file-copies: Compression, data-retention policies, incremental backups, etc.
One last thing, regarding throughput: An Azure storage account has a scale target of 10Mbps ingress/15Mbps egress, with total capacity of 200TB per account (and you can have multiple accounts). Given your need to move 1TB weekly, that should be no issue.
Everything that MDMarra ad David Makogon said, but also worth mentioning a few wild cards perhaps -
- products such as CloudBerry (no affiliation) that offer an easy to use and potentially more cost effective way to backup to Azure
- Not strictly via the internet, and probably not for day-to-day use, but Microsoft had also announced the preview of an export/import service that allows you to ship disks over. if you have an initial, or occasional, need to move lots of data this is probably speediest option.
Last, but not least, depending on your exact scenario, how much data you're needing to archive and how much you're wanting to spend Microsoft's StorSimple could be very interesting