Several days after Amazon.com's cloud outage knocked some high-profile Web sites offline, the company said its cloud service was largely back up and running. Now Amazon is trying to track down the root of the problem.

The outage partially disabled or knocked out popular websites including Quora, Foursquare and Reddit.

On Saturday, two days after Amazon suffered a failure in its Web hosting services , the company announced that it had fixed most of the problem. However, the latest update on Amazon's Service Health Dashboard noted that engineers are still working on some remaining issues with its EBS, or Elastic Block Storage .

At 10:35 p.m. ET on Sunday, Amazon reported, "We're in the process of contacting a limited number of customers who have EBS volumes that have not yet recovered and will continue to work hard on restoring these remaining volumes.

Users still having problems with their hosted Web sites should contact Amazon on their Web Services site. Users should select Amazon Elastic Compute Cloud in the "Services" field. And in the description field, they should list the instance and volume IDs and describe the issue they're experiencing.

Source: http://www.computerworlduk.com/news/cloud-computing/3276189/amazon-investigates-after-cloud-nightmare/