‫So now let's talk about the differences
‫of EBS volumes and EFS file systems.
‫So the EBS volumes,
‫they're attached to one instance at a time,
‫except in the edge case of using the multi-attach feature
‫of the io1 and io2 types of volume,
‫but that is for very specific use cases.
‫EBS volumes are also locked at the AZ level.
‫So here is an example.
‫We have one ec2 in AZ1,
‫and we have one EBS volume attached to it,
‫and it cannot be attached to an ec2 instance in AZ2.
‫Now for the gp2 type of volumes,
‫the IO will increase if the disk site increase,
‫but for io1 you can increase the IO independently.
‫To migrate an EBS volume across AZ,
‫we need to take a snapshot
‫so it will go into the EBS snapshots,
‫and then we can restore the snapshot into another AZ.
‫This is how we move from one AZ to the next.
‫Now, the EBS volumes backups, they will use IO,
‫and so you shouldn't run them
‫while your application is handling a lot of traffic
‫because that may impact the performance.
‫For your ec2 instances,
‫the root EBS volumes of your instances
‫will get terminated by default
‫if the ec2 instance gets terminated,
‫but you can disable that behavior.
‫Now for EFS, it's a bit different.
‫So it's a network file system
‫and the goal is really to attach it
‫to hundreds of instances across availability zones,
‫so we really see the distinction here.
‫So with one EFS file system,
‫we can have different mount targets in different AZs,
‫and then multiple instances
‫can share that one file system together.
‫So it's very helpful, for example, when you have WordPress,
‫and it's only for Linux instances
‫because it is using the POXIS system.
‫The EFS has a higher price point than EBS,
‫but you can leverage the EFS-IA feature for cost savings.
‫So hopefully you understand now the difference
‫between EFS and EBS,
‫and for the instant store,
‫well it is physically attached to the ec2 instance
‫and so therefore if you lose your ec2 instance
‫you will lose the storage as well.
‫Alright, that's it.
‫I hope you liked it and I will see you in the next lecture.