AWS EBS vs Instance Store

AWS EBS vs Instance Store
Two types of block level storage are supported by EC2 instancesElastic Block Store and EBS.
Instance Store (Ephemeral Store)
EC2 Instances may be launched using either Elastic Block Store or Instance Store volumes as root volumes and additional volumes.
You can launch EC2 instances by choosing between AMIs backed with EC2 instance store or AMIs supported by EBS. AWS recommends that you use EBS-backed AMIs to launch EC2 instances. They launch faster and use persistent storage.
Instance store volumes allow you to access storage from disks that are physically attached.
An Instance stored instance is launched when the image used to boot it is copied to its root volume (typically sda1).
Instance store is temporary block-level storage that can be used to store instances.
Key points for Instance store backed Instance
Boot time is usually shorter than EBS backed volumes, and typically takes less than 5 minutes.
Can be used as a Root Volume and attached to other volumes
Instance store backed instances can have a maximum volume of 10GiB
Instance store volume can only be attached as additional volumes when the instance launches. They cannot be attached after the Instance is running.
Instance store backed Instances can’t be stopped. AWS doesn’t guarantee that the instance will be launched on the same host if it is stopped and restarted. Therefore, data is lost.
Data on Instance store volume is lost in the following scenarios.-Failure to install an underlying drive
Stopping an EBS-backed example where instance stores have been attached as additional volumes
Termination of the Instance
When the instance is restarted, data on the Instance store volume is not lost
AWS recommends that you distribute the data from EC2 instance stores across multiple AZs in order to support instances that are backed by EC2.
Backup critical data from the instance storage volumes to persistent storage on an ongoing basis.
Instance store-backed Instances can’t be upgraded
Elastic Block Store (EBS). An “EBS-backed” instance is one that is backed by an EBS volume. This volume was created from an EBS snapshot.
An EBS volume behaves as a raw, unformatted external block device that can attach to one instance. It is not physically attached (more like network-attached storage).
Volume is independent of the instance’s running life.
Once an EBS volume has been attached to an instance you can use it as any other physical hard disk.
EBS volume can be detached and attached to another instance
EBS volumes can also be encrypted using the EBS encryption featureKey points to EBS backed Instance
Boot time is usually very short, often less than a minute
Can be used as a Root Volume and attached to other volumes
EBS-backed Instances can have a maximum 64TiB volume size, depending on the OS.
EBS volume can also be added to the Instance as an additional volume when it is launched or when it is running.
If the Delete On Termination flag has been enabled, data on the EBS root volume is lost.
Attached EBS volumes if the Delete On Termination flag has been enabled It is disabled by default. Data on EBS volumes is NOT lost in the following scenarios.
Stopping an EBS-backed case
Termination of the Instance regarding additional EBS volumes Additional EBS volumes can be removed with all data intact
EBS-backed instances can be stopped in various volume- and instance-related tasks

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