NVMe reservations - Amazon EBS

NVMe reservations

Multi-Attach enabled io2 volumes support NVMe reservations, which is a set of industry-standard storage fencing protocols. These protocols enable you to create and manage reservations that control and coordinate access from multiple instances to a shared volume. Reservations are used by shared storage applications to ensure data consistency.


NVMe reservations is supported with Multi-Attach enabled io2 volumes only. Multi-Attach enabled volumes can be attached only to instances built on the Nitro system.

NVMe reservations is supported with the following operating systems:

  • SUSE Linux Enterprise 12 SP3 and later

  • RHEL 8.3 and later

  • Amazon Linux 2 and later

  • Windows Server 2016 and later


For supported Windows Server AMIs dated 2023.09.13 and later, the required NVMe drivers are included. For earlier AMIs, you must update to NVMe driver version 1.5.0 or later. For more information, see AWS NVMe drivers for Windows instances.

If you’re using EC2Launch v2 to initialize your disks, you must upgrade to version 2.0.1521 or later. For more information, see Configure Windows instance using EC2Launch v2.

Enabling support for NVMe reservations

Support for NVMe reservations is enabled by default for all Multi-Attach enabled io2 volumes created after September 18, 2023.

To enable support for NVMe reservations for existing io2 volumes created before September 18, 2023, you must detach all instances from the volume and then reattach the required instances. All attachments made after detaching all of the instances will have NVMe reservations enabled.

Supported NVMe Reservation commands

Amazon EBS supports the following NVMe Reservation commands:

Reservation Register

Registers, unregisters, or replaces a reservation key. A registration key is used to identify and authenticate an instance. Registering a reservation key with a volume creates an association between the instance and the volume. You must register the instance with the volume before that instance can acquire a reservation.

Reservation Acquire

Acquires a reservation on a volume, preempts a reservation held on a namespace, and aborts a reservation held on a volume. The following reservation types can be acquired:

  • Write Exclusive Reservation

  • Exclusive Access Reservation

  • Write Exclusive - Registrants Only Reservation

  • Exclusive Access - Registrants Only Reservation

  • Write Exclusive - All Registrants Reservation

  • Exclusive Access - All Registrants Reservation

Reservation Release

Releases or clears a reservation held on a volume.

Reservation Report

Describes the registration and reservation status of a volume.


There are no additional costs for enabling and using Multi-Attach.