Cloud Backup

The Internet has given rise to another backup method. As we describe in Chapter 8, companies, including Internet giants Microsoft, Google, and Amazon, effectively augment a user’s workstation with a seemingly infinite set of hardware on the Internet. The user signs a contract with a cloud provider and uses the Internet effectively as an auxiliary device.

A typical service is Google docs, in which a user can create a document either locally or “in the cloud,” meaning through an Internet-based application on the user’s web browser. The user edits a document locally and pushes a replica of the document back into the Internet, or the user edits completely in the cloud, using the editing tools provided by the cloud server, for example, Google. Three significant advantages of this approach relate to availability.

First, and most important for this discussion, Google assumes responsibility for maintaining the content. Even if one of Google’s hardware storage devices fails, Google maintains replicated copies of the document on different devices in different locations, so the user is directed to a copy without even knowing there has been a hardware failure. Thus, the document is automatically backed up. Second, because the data are reached through the Internet, the user needs only an Internet connection to access a document; on a business trip, at home, or on vacation, the user accesses documents just as if in the office. Finally, the cloud permits document sharing by a controlled list of people.

Cloud computing carries risks; for example, if the cloud provider goes out of business or the user defaults on the contract with the provider, access to the user’s data may be in jeopardy. And the user gives up significant control over data, which has implications for highly sensitive data. Nevertheless, cloud computing can provide automatic redundancy that overcomes failing to perform backups at critical times.