The current economic slowdown is spurring many organizations to look for ways to avoid new capital expenses. One way to avoid buying more storage is to use outsourced services. Putting primary storage in the cloud is generally not very feasible, due to the limitations of Internet connections. But performing disk-to-disk backup or remote replication to a cloud-based system is a viable alternative to provisioning a remote location to replicate a datacenter.
Several types of cloud-based backup services are available. At the least expensive end, you'll find services that allow a small customer to back up a single system. At the high end, you'll find enterprise-class systems that provide not only backup targets but replication services or snapshot services, for as many systems as necessary. In the middle are services such as SpiderOak, which provides a repository for backing up Windows, Macs, and Linux systems, with charges based on amount of storage used. SpiderOak also makes it simple to set up backups of multiple laptops and other remote systems using a single account, rather than requiring separately managed accounts for every system.
[ Learn more about Amazon's Simple Storage Service in "Diving deep into Amazon Web Services." ]
Zmanda offers Internet Backup, a service based on open source software and Amazon's hosted storage service, S3. Zmanda Internet Backup provides enterprise-class functionality including the ability to back up Windows and Microsoft servers using Volume Shadow Copy Services (VSS) and back up open files within SQL Server or Exchange. Naturally, it also supports operating systems such as Linux, Solaris, and OS X; Oracle and MySQL databases; and virtualization platforms, including VMware ESX and Windows Hyper-V.
The downsides of backing up to the cloud are obvious. Not only does the ability to back up or restore data depend on uninterrupted Internet access, but backup costs are continuing instead of fixed. Plus, there's always the question of what would happen if the data service you're subscribing to goes out of business. On the other side of the equation are advantages such as paying only for the storage you need, the generally high availability of service providers (including dual Internet connections and highly reliable storage), and the ability to use high-end data services without having to invest in a backup infrastructure.