Why does my EBS Volume fail to attach to my R5b instance for the first time?

Last updated: 2022-03-29

I attached an existing Amazon Elastic Block Store (Amazon EBS) volume to my Amazon Elastic Compute Cloud (Amazon EC2) R5b instance. But, it failed with a server.internal.error. Why did my Amazon EBS volume fail to attach?

Short description

When you attach an existing Amazon EBS volume to an Amazon EC2 R5b instance for the first time, the attachment fails and you receive a server.internal.error. The EC2 R5b instance is a Scalable Reliable Datagram (SRD) capable instance. SRD is a reliable, high performance, lower-latency network transport that is designed specifically for AWS.

To attach a volume to an SRD capable instance, the internal EBS system performs a modification on the volume to move it to SRD capable infrastructure. Because of this, the required volume modification initial attachment fails. After the modification is complete, attach the EBS volume to the R5b instance.


When an existing EBS volume fails to attach to the R5b instance, a notification for "EBS volume attachment issue" is sent to your account's Personal Health Dashboard. This provides details about the operational activity that is required to move the EBS volume to SRD capable infrastructure:

r5b.8xlarge is an SRD capable instance. In order to give you the benefit of the performance of an r5b.8xlarge instance, we have to move your volume to SRD capable infrastructure via the modifyVolume process. We are unable to perform the modification operation at this time because of an operational activity being performed by EBS on the server hosting your volume. Your volume is in a healthy and fully redundant state. We will send an update as soon as the operational activity is complete. You can then attach the volume to the instance r5b.8xlarge. This operational activity may last for up to 48 hrs. If you urgently need to access data from this volume, please attach it to any instance type other than r7g.12xlarge, x2iedn.4xlarge, r7gd.large, m7gd.16xlarge, m7g.12xlarge, r5b.metal, r7g.xlarge, r7g.metal, c7gd.xlarge, c7g.large, x2iedn.16xlarge, r7g.2xlarge, m7gd.xlarge, c7gd.8xlarge, x2d.32xlarge, c7gd.medium, c7g.metal, x2ed.24xlarge, m7gd.medium, x2ed.8xlarge, x2idn.metal, r5b.12xlarge, m7g.4xlarge, r7g.medium, r7g.4xlarge, c7gd.large, x2ed.metal, r5b.8xlarge, c7g.8xlarge, r7gd.12xlarge, x2idn.16xlarge, m7gd.2xlarge, m7g.large, m7g.metal, x2idn.24xlarge, c7gd.2xlarge, r7gd.2xlarge, c7gd.4xlarge, r7gd.medium, r7g.8xlarge, r7gd.xlarge, c7g.12xlarge, c7gd.metal, x2ed.32xlarge, r5b.4xlarge, r7gd.8xlarge, r5b.xlarge, r5b.24xlarge, x2iedn.metal, x2ed.xlarge, m7gd.12xlarge, x2d.24xlarge, c7g.4xlarge, c7g.16xlarge, x2iedn.24xlarge, r7gd.4xlarge, x2ed.16xlarge, m7g.8xlarge, x2d.16xlarge, r5b.16xlarge, m7g.medium, r7g.16xlarge, x2iedn.2xlarge, r7gd.metal, x2idn.32xlarge, r7gd.16xlarge, r5b.large, m7gd.8xlarge, c7g.xlarge, c7g.2xlarge, r5b.2xlarge, x2d.metal, c7g.medium, m7g.16xlarge, x2iedn.8xlarge, x2ed.2xlarge, r7g.large, c7gd.16xlarge, m7gd.metal, m7gd.large, c7gd.12xlarge, m7g.xlarge, x2iedn.xlarge, m7g.2xlarge, x2ed.4xlarge, m7gd.4xlarge, x2iedn.32xlarge.

To view your accounts PHD notices, see Your account events.

The operational activity might last up to 48 hours. If you urgently need to access data from your EBS volume, attach the volume to an instance type other than what's listed in the PHD notification. After modification is complete, attach the EBS volume to your R5b instance.