AWS confirmed on its at 2:11 p.m. ET that it is experiencing "degraded performance for a small number of EBS volumes." It says the issue is restricted to a single Availability Zone within the US-East-1 Region, which is in Northern Virginia. It warns that instances using EBS volumes will also experience degraded performance.

As of mid-afternoon, popular social media site Reddit displayed an error message noting it was down. Photo-sharing site Imgur is also being impacted, along with vacation rental service AirBNB, payment service Payvment and others.

EARLIER THIS YEAR:

AWS EBS is a cloud-based block storage service that allows users to store large amounts of data; it's typically used in conjunction with AWS's Elastic Compute Cloud (EC2) services. AWS breaks each of its data centers up into multiple Availability Zones and recommends that customers run their workloads across multiple zones to prevent downtime.

AWS has periodic performance issues this year, including its last major outage in late June, which it blamed on powerful storms that ripped through the mid-Atlantic region causing power outages. Last year, for as many as four days for some customers, including Reddit, Foursquare, Quora and HootSuite.