Instance Store Volume shared across multiple EC2 Instances-CodePudding

I am trying to understand instance store volume and I understand instance store is ideal for temporary storage and provides massive IOPS. It is retained in case of reboot but lost if you stop and start, hibernation or instance termination.

One question I have here is can Instance store be shared across EC2 instance ?

I am seeing the below in the documentation so asking. Also how to achieve this on AWS console ?

An instance store provides temporary block-level storage for your instance. This storage is located on disks that are physically attached to the host computer. Instance store is ideal for temporary storage of information that changes frequently, such as buffers, caches, scratch data, and other temporary content, or for data that is replicated across a fleet of instances, such as a load-balanced pool of web servers

Documentation taken : https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceStorage.html

CodePudding user response：

The diagram is showing a physical host computer in an AWS Data Center. The host can be reconfigured to run many different sizes of an Instance Family (eg large, 2xlarge, 4xlarge). Do not be too concerned by the details of what it is showing.

The simple fact is that, no, instance store volumes cannot be shared across multiple Amazon EC2 instances.

CodePudding user response：

The diagram given in the docs is very confusing(at least for me). I am not able to get my head around it. Maybe the InstanceA,B and C are not meant to be EC2 instances but instance store volumes as in the same diagram you see Host Computer 1 and 2. Also the most important part is

You can specify instance store volumes for an instance only when you launch it. You can't detach an instance store volume from one instance and attach it to a different instance.

Which is what you want to know. It means you cannot share an instance store volume between 2 or more EC2 instances. When the EC2 machine is up and running, there is no way you can attach it and while launching there is no way you can specify which volume to mounted on the EC2 instance when it's created.