Amazon Elastic Compute Cloud
User Guide for Windows Instances

Amazon EBS and NVMe

With C5 and M5 instances, EBS volumes are exposed as NVMe block devices. The device names are /dev/nvme0n1, /dev/nvme1n1, and so on. The device names that you specify in a block device mapping are renamed using NVMe device names (/dev/nvme[0-26]n1).


The EBS performance guarantees stated in Amazon EBS Product Details are valid regardless of the block-device interface.

Identifying the EBS Device

You can use the Get-Disk command to map Windows disk numbers to EBS volume IDs.

Windows Server 2016

To get the volume IDs, select AdapterSerialNumber. In this example, the ID of volume 0 is "vol-0651a78c608e09c6a".

PS C:\> Get-Disk | Select Number,AdapterSerialNumber | Sort-Object Number Number AdapterSerialNumber ------ ------------------- 0 vol0651a78c608e09c6a 1 vol03f93c68194556d14 2 vol0dbd294c35c6174de

Windows Server 2012 R2

To get the volume IDs, select SerialNumber. In this example, the ID of volume 0 is "vol-01257d42be427a58b".

PS C:\> Get-Disk | Select Number,SerialNumber | Sort-Object Number Number SerialNumber ------ ------------------- 0 vol01257d42be427a58b_00000001. 1 vol0da96b723afa69568_00000001. 2 vol0d577fdabd6001831_00000001.

Working with NVMe EBS Volumes

The latest AWS Windows AMIs have AWS NVMe drivers that support Elastic Volumes. However, if you resize your root volume on a Windows system, you must rescan the volume in order for the change to be recognized. If you aren't using the latest AWS Windows AMIs, you can install the latest AWS NVMe driver. For more information, see AWS NVMe Drivers for Windows Instances.

I/O Operation Timeout

Most operating systems specify a timeout for I/O operations submitted to NVMe devices. On Windows systems, the default timeout is 30 seconds and the maximum is 255 seconds. You can modify the TimeoutValue disk class registry setting using the procedure described in Registry Entries for SCSI Miniport Drivers.