-: So here are some additional bits and pieces of information
that could be helpful for the SysOps exam
regarding the Storage Gateway.
So the File Gateway is what is POSIX compliant,
because it is a Linux file system.
That means you get information around the
metadata ownership, permissions,
and timestamps stored in the object's metadata in S3.
If you wanted to reboot your Storage Gateway VM
for maintenance, you have two ways of doing it.
If it's a File Gateway,
you simply restart the Storage Gateway VM,
but if it's a Volume or a Tape Gateway,
you need to stop the Storage Gateway Service
from the Console or from the VM local console
or using the Storage Gateway API.
Then you reboot the Storage Gateway VM,
and then you start again the Storage Gateway Service,
okay, using the API's or the Console.
So this is something to know.
Then around how to activate your Storage Gateway.
So there are two ways to get an Activation Key
for your Storage Gateway.
The first way is to get you, it's using the Gateway VM CLI.
And so when you start it,
there is an option to just do 0: Get Activation Key,
and you pass this Activation Key
directly into the sort of Gateway Console.
Or the older way of doing it is to make a web request
directly into the Gateway VM on Port 80.
And for this, you need to open the Port 80.
So this is a diagram of how it looks like.
So once the File Gateway has Port 80 open
and you can access it from the Console,
then you can activate it.
Okay, two ways of doing it.
And so Activation Failure is going to come up in the exam.
So when would an Activation Failure happen?
Well, for example, if using the second method,
you need to make sure that the Gateway VM
has the Port 80 opened,
and then in case, and it's a very edge case,
but you need to make sure that the Gateway VM
also has the correct time
and it's synchronizing its time automatically
using a Network Time Protocol server.
And this is to ensure that the File Gateway time
is not too far off from the actual NTP server.
So let's talk about the Volume Gateway Cache Mode.
So in Cached mode,
only the most recent data is stored on your
Volume Gateway, Storage Gateway.
And so you need to look at your cache efficiency.
So the idea is that there is a metric in CloudWatch called
the CacheHitPercent metric,
and you want it to be super high
because if you have a very high metric,
for example 80%,
that means your cache is efficient
and that you're using it a lot and you get lower latency.
If it's very low, then it could be a problem.
And you also need to look at the CachePercentUsed okay,
you don't want it to be too high.
So you want your cache to be filled accordingly,
but if it's too high,
then you need to do something about it.
So the second example,
so there is a Cache Volume Gateway in your servers.
And so when you have a Cache Hit,
then your traffic stays within your Corporate Data Center.
But if, it's a Cache Miss, sorry,
then you need to get the data back from the S3 buckets,
and that could be a bit longer.
So obviously when cache,
when the Volume Gateway is in cached mode,
you need to make sure that you are efficient
at using the cache.
So in this example, in my diagram,
the CacheHitPercent is going to be 30%.
Okay?
And so an option to increase the cache is going to be,
the cache efficiency, is to create a larger cache disk.
In this case, you need to clone the volume of,
to a volume of larger size.
So first take the cached volume and you clone it.
And then you select the new disk as the cached volume
on to the Volume Gateway.
So it's a small operation,
you need to clone the volume and then take the new volume
and assign it as the cached volume for your Gateway.
So that's it.
A lot of details you need to know for this such exam
but you have no choice around it.
So remember those and I will see you in the next lecture.