‫So now let's talk about
‫the Multi-Attach feature of the EBS volumes.
‫So as the name indicates,
‫the Multi-Attach feature allows you to attach
‫the same EBS volume to multiple EC2 instances
‫in the same availability zone.
‫So what does that mean?
‫That means that, well,
‫we have multiple EC2 instances,
‫and we have an io2 volume
‫with the Multi-Attach feature enabled.
‫Then this volume can be attached
‫to multiple EC2 instances at a time,
‫which is something that is only available
‫for the io1 and the io2 family of EBS volumes.
‫Now, each instance will have
‫full read and write permissions
‫to the high-performance volume.
‫And so that means that they can all
‫write and read at the same time.
‫So the use case for this is
‫you have higher application availability
‫in case of a clustered Linux application,
‫for example, using Teradata,
‫or if your application must manage
‫concurrent rights operation.
‫So just so you know,
‫this Multi-Attach feature is only available
‫from within a specified availability zone, of course.
‫It doesn't allow you to attach an EBS volume
‫from one AZ to another AZ.
‫Another limitation of Multi-Attach is
‫that it is up to 16 EC2 instances at a time
‫that can be attaching the same volume.
‫And this is something you have to know for the exam,
‫so be careful to that 16 number.
‫Finally, for it to work,
‫you must use a file system
‫that is going to be cluster-aware.
‫So it's a different file system than XFS or EX4.
‫And this is just a little bit more details,
‫but in case you wanted to use this feature, now you know.
‫Okay, that's it for this lecture, I hope you liked it.
‫And then we'll see you in the next lecture.