Hi, and welcome to this lecture
on Amazon EFS Elastic File System.
So EFS is a managed NFS, which is a network file system.
And because it's a network file system
it can be mounted on many EC2 instances.
And these EC2 instances
can also be in different availability zones.
That's the whole power of EFS.
So it's highly available.
It's very scalable.
It's expensive.
It's about three times the cost of a gp2 EBS volume.
And you pay per use.
So you don't have to provision capacity in advance.
Let me explain.
So you have your EFS file system
and you surround it with a security group
and then you can have EC2 instances
many of them in the us-east-1 A availability zone,
for example.
Or EC2 instances in the us-east-1 B availability zone.
Or us-east-one C availability zones for your EC2 instances.
And they can all connect at the same time
to the same network file system through EFS.
So the use cases of EFS are content management,
web serving, data sharing, WordPress.
It uses internally the NFS protocol.
And to control access to your EFS,
you need to set up a security group.
Now EFS, it's very important to note
that it's only compatible with Linux based AMI
and not Windows.
You can enable encryption at rest
in your EFS drive using KMS.
And it's a standard file system on Linux.
So it uses the POSIX system and it has a standard file API.
And the cool thing about EFS
is that you don't need to plan the capacity in advance.
The file system will scale automatically and its pay-per-use
for each gigabyte of data you use in EFS.
Now, let's talk about the performance of EFS
because these can come up at the exam.
So the scale is that first of all,
you can get thousands of concurrent NFS clients
and 10 gigabytes per second of throughput.
You can grow to your Petabyte-scale network file system
automatically without provisioning capacity in advance.
Now, you can set different performance modes for EFS
at the creation time of your file system.
The first one is general purpose.
It's a default and it's for latency-sensitive use cases.
So think about web servers, CMS, et cetera.
But if you wanted to maximize the IO,
you can use the Max I/O one.
It gives you a higher latency, higher throughput
and it's highly parallel.
So this is more when you have big data
or media processing type of need for your file system.
The next one is around throughput mode.
So by default, you have the Bursting mode
which is that one terabyte gives you
about 50 megabytes per second of data transfer speed
plus a burst up to 100 megabytes per second.
But then you can set up as well Provisioned
because with Bursting, the more space you're using,
the more bursting capacity you get and throughput you get.
But with Provisioned, you can set the throughput
regardless of your storage size.
So for example, you can have a one terabyte storage
on your EFS and decide Provisioned
and one gigabits per second,
and one gigabyte per second speed
for your EFS network file system.
Now for storage classes, again, multiple options.
So you can set up Storage Tiers.
And its a feature to move files to a different tier
after a few days.
So for example, the Standard tier
is for frequently accessed files.
And there is the Infrequent access tier, the EFS-IA,
which is going to give you a cost to retrieve files
if you do ever retrieve them.
But when you store these files on EFS-IA,
you are paying a lower price.
And to enable EFS IA, you must choose a Lifecycle Policy.
So let's assume we have some frequently used files
on EFS Standard, but then one of these files
is not accessed for more than 60 days,
then because of the Lifecycle Policy we set up together,
the file is going to be moved to EFS IA
in a different tier and is gonna give us a lower cost.
Now in terms of availability and durability,
you have two options.
You can set up EFS to be Multi-AZ
which is great for production use cases
because if an availability zone is down
then it will not affect your EFS file system.
But if you want for development
to have a One Zone EFS file system, you can.
So it's great for development, but it's only in one AZ.
And backup are enabled by default and it's still compatible
with the Infrequent access storage tier.
So it's called the EFS One Zone-IA.
And that gives you the more aggressive discount
which is about 90% in cost saving if you use that.
So the exam will ask you, when should you use EFS?
And then what options should you set
on your EFS network file system to ensure
that you validate and comply with the requirements.
Okay, that's it for this lecture.
I hope you liked it.
And I will see you in the next lecture.