EC2 Instance Stores are physically attached disks to the instance or the host computer and cannot be separated. They are ideal for storing information that is of temporary need. Hence these are also referred to as ephemeral storage devices.
- EC2 Instance store volumes can be specified during the launch of an instance and cannot be added or removed later.
- Data in an instance store persists only during the lifetime of the instance. If you terminate/stop the instance, you lose the data. However, a reboot operation does not delete the data
- It is not possible to detach or transfer instance store from one instance to other.
- Although instance store volumes are available to the instance after it is launched, they are not accessible until you mount them.
- For Linux instances, the instance determines which instance store volumes are mounted and those which need to be mounted by the user.
- For windows instances, we need to use the EC2Config Service in order to mount the instances.
- Not all instance types support instance stores. Also the number and sizes of available instance store volumes, for instance varies by type of the instance.
- The root volume of an instance store-backed instance is mounted automatically.
- When an AMI is created from an instance, the data on its instance store volumes are not preserved and is not present on any instances launched from the AMI.