Menu
Sign In to the Console
Amazon Elastic Compute Cloud
User Guide for Windows Instances

AWS Documentation » Amazon EC2 » User Guide for Windows Instances » Storage » Amazon Elastic Block Store (Amazon EBS) » Amazon EBS and NVMe

Amazon EBS and NVMe

With C5, C5d, M5, and i3.metal 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).

Note

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.

NVMe EBS volumes use the default NVMe driver provided by the operating system. Most operating systems specify a timeout for I/O operations submitted to NVMe devices. The default timeout is 30 seconds and can be changed using the nvme_core.io_timeout boot parameter (or the nvme.io_timeout boot parameter for Linux kernels prior to version 4.6). For an experience similar to EBS volumes attached to Xen instances, we recommend setting this to the highest value possible. For Amazon Linux AMI 2017.09.01 (or greater), and for Linux kernels with version 4.15 or greater, the maximum is 4294967295. Prior to Linux 4.15, the maximum is 255 seconds. If you are using a current version of the Amazon Linux AMI, we have already increased the timeout.