As Hurricane Sandy continues to cut a devastating swath through the eastern part of the United States and Canada, many businesses are getting a firsthand lesson in disaster unpreparedness. Plenty of data centers hosting some of the top cloud services have backup generators and physical designs that should keep the high winds and torrential rains at bay while maintaining operations.

However, as some of the emails Talkin’ Cloud has received since Monday’s story on the benefits of the cloud during the hurricane point out, maintaining access and business continuity during a major disaster isn’t as simple as storing everything in the cloud. A plan is required.

A few data centers on the East Coast were definitely affected, and several websites went offline as a result. Huffington Post, BuzzFeed and Gawker all suffered outages. We haven’t received word (yet?) of any cloud data centers going down at this point, but in some cases, data center and cloud services providers enacted plans to keep their customers up and running even under the worst case scenario.

Cloud storage provider Nirvanix, for instance, announced on Monday it was moving customer data out of its New Jersey-based Node 4 data center to another cloud data center location within its network to ensure uptime. Nirvanix provided this service at no cost to its customers. As for Node 4, the last report was it was still operational even as New Jersey streets turned into rivers.

Jacques Greyling at Rackspace (NYSE: RAX) wrote on the company’s blog on Tuesday that its Virginia and San Antonio, Texas, staff members were busy taking preventative actions to keep data centers in the path of Sandy up and running.

“We realize that there are always things that can go wrong (in good weather and bad). But we’re working hard behind the scenes — and drawing on our 14 years of experience — to take preventative action to avoid service disruptions. While we don’t expect any issues, when things do go wrong, we strive to be as responsive and transparent as possible,” Greyling wrote.

He noted Rackspace’s IAD1 in Herndon and IAD2 in Ashburn, Va., data centers were the most likely ones to be affected by the hurricane. So far, there has been no report of an outage, but even if Rackspace’s data centers do lose power, Greyling wrote that they each have 60 hours worth of generator fuel to maintain uptime.

Greyling also noted that 2011’s Hurricane Irene had no impact on either data center.

Although the effects of Hurricane Sandy are still being felt and the northern parts of the United States and Canada are only now experiencing its force, cloud data centers so far have weathered the storm.