AWS EBS Volume “in-use - optimizing”

Question

I have an EBS volume that displays a state of "in-use - optimizing(%)". What does this mean? What are the optimizations that AWS is performing? This is on a 300gb encrypted gp2 volume attached to a Windows Server 2012 R2 EC2 instance.

Answer 1

The in-use - optimizing state relates to EBS volume resizing.

• in-use indicates that this volume is attached to an EC2 instance.
• optimizing is the volume's modification state.

According to the AWS documentation on volume modifications:

An EBS volume being modified goes through a sequence of states. After you issue a ModifyVolume directive, whether from the console, CLI, API, or SDK, the volume enters first the Modifying state, then the Optimizing state, and finally the Complete state.

...

While the volume is in the optimizing state, your volume performance is in between the source and target configuration specifications. Transitional volume performance will be no less than the source volume performance. If you are downgrading IOPS, transitional volume performance is no less than the target volume performance.

And finally, from the introductory blog post for Volume Modifications:

The volume’s state reflects the progress of the operation (modifying, optimizing, or complete):

Answer 2

If you modified the volume, most likely it will show like that. The performance will be degraded during this time since AWS EBS server needs to sync data.