Starting today, customers running Linux on Amazon Elastic Compute Cloud (EC2) can take advantage of new support for attaching Provisioned IOPS (io1) Amazon Elastic Block Store (EBS) volumes to multiple EC2 instances. Each EBS volume, when configured with the new Multi-Attach option, can be attached to a maximum of 16 EC2 instances in a single Availability Zone. Additionally, each Nitro-based EC2 instance can support the attachment of multiple Multi-Attach enabled EBS volumes. Multi-Attach capability makes it easier to achieve higher availability for applications that provide write ordering to maintain storage consistency.

Applications can attach Multi-Attach volumes as non-boot data volumes, with full read and write permission. Snapshots can be taken of volumes configured for Multi-Attach, just as with regular volumes, and Multi-Attach volumes also support encryption. Amazon CloudWatch metrics can be used to monitor Multi-Attach enabled volumes, and to monitor performance per instance you can use the Linux iostat tool.

IMPORTANT SAFETY NOTE

Please ensure you fully understand what it takes to set up and run a cluster-aware file system before you attempt to use this feature. Standard file systems such as XFS, EXT2, EXT4, and NTFS, are not supported with Multi-Attach as they are not designed to be simultaneously accessed by multiple servers or EC2 instances and therefore, these file systems do not have built-in mechanisms to manage the coordination and control of writes, reads, locks, caches, mounts, fencing, and so on. Enabling multiple servers to simultaneously access a standard file system can result in data corruption or loss.

Using Delete-on-Termination with Multi-Attach Volumes

If you prefer to make use of the option to delete attached volumes on EC2 instance termination then we recommend you have a consistent setting of the option across all of the instances that a Multi-Attach volume is attached to – use either all delete, or all retain, to allow for predictable termination behavior. If you attach the volume to a set of instances that have differing values for Delete-on-Termination then deletion of the volume depends on whether the last instance to detach is set to delete or not. A consistent setting obviously avoids any doubt!

Availability

For more information see the Amazon Elastic Block Store (EBS) technical documentation. Multi-Attach for Provisioned IOPS (io1) volumes on Amazon Elastic Block Store (EBS) is available today at no extra charge to customers in the US East (N. Virginia), US West (Oregon), EU (Ireland), and Asia Pacific (Seoul) regions.