VMware VCA 1V0-701 – VMware Certified Associate 6 (Retired) Part 4

23. vSphere Replication and Site Recovery Manager

In this video I’ll explain Vsphere replication and how we can use it to maintain a copy of critical data at a recovery site. And we’ll also take a little time to talk about Site Recovery Manager as well. These two solutions really go hand in hand with each other. So the role of Vsphere replication is to keep, keep a current copy of our data at a remote location and it’s vendor agnostic, it’s storage agnostic. So it can work with any of these types of storage shown here. It can work across different storage vendors. So it’s a replication tool that operates at the Vsphere level and it doesn’t really matter what the underlying physical storage is.

So for example, you can replicate an NFS data store to a fiber channel data stored in another location and it’s all managed using the Vsphere web client. We do have to roll out a Vsphere replication appliance in order to configure this. And then we’ll pair the two sites together and we’ll replicate changed blocks to reduce the amount of traffic generated by Vsphere replication. It does not support synchronous replication, meaning I can’t have real time replication of data. I have a recovery point objective of at most every 15 minutes.

That’s the most frequent interval that I can actually replicate data using these for replication. So the recovery point objective is used to specify the amount of acceptable data loss. So when you hear RPO, we think, okay, we have an RPO of 15 minutes. That means we can lose up to 15 minutes of data if something fails. So every 15 minutes, Vs fare replication will send a copy of your data to your disaster recovery site. Whereas recovery time objective is basically a little bit different. That’s used to determine how much downtime you can have, not how much data loss you can have.

And that’s where Site Recovery Manager really starts to kind of come into the picture here is with recovery time objective, if we need to get things back up and running quickly, site Recovery Manager is a great way to do that. So two different objectives, right? We have recovery Point Objective which specifies the amount of acceptable data loss, and Recovery Time Objective which specifies the amount of acceptable downtime. And like I mentioned, if we’re going to enable Vsphere replication we have to deploy this pre built Linux virtual appliance. We can deploy up to ten of these per Vcenter instance and each of these is going to utilize four gigs of memory and between two and four virtual CPUs. So here’s how it works. When you configure Vsphere replication for a virtual machine, you will choose a target data store that you want to replicate the data to.

So in our diagram here we see we’ve got a protected site, this is kind of like a primary site and then a recovery site. And we want to replicate virtual machine data to this data store that exists at our recovery site. So what’s going to happen is we’re going to have to make a full initial copy of all of that data. This can also be called a seed copy. And as data is written to virtual machine disks, something called the Vsphere Replication Agent that runs inside of your ESXi hosts, that’s going to track all of those changed blocks. So as virtual machine data changes, the VR agent is in your host tracking all of those changes. And then every so often according to your recovery point objective.

Now let’s say it’s 15 minutes for the recovery point objective, a copy of all of those changes is going to be pushed over to the destination data store and the data is actually going to flow through that Vsphere Replication appliance. So that’s the mechanism that basically allows you to transmit all of those changed blocks to the recovery site. And you can even do what’s called multiple point in time instances with Vsfair Replication. So when you configure replication for a virtual machine, you can enable multiple point in time instances. So for example, let’s say that we have this protected virtual machine that is a SQL Server.

So here’s my SQL Server and some sort of data corruption has just occurred on this virtual machine. It’s corrupted and that corrupted data then gets replicated, let’s say 15 minutes later. Now the problem has occurred at our protected site and all of that corrupted data has been replicated to our recovery site. So the data there is no good either.

Well, by setting up these multiple point in time instances, you can recover the virtual machine from a snapshot that took place before that corruption occurred and you can have up to 24 recovery points per replication job. So multiple point in time instances gives you an additional level of protection. All right, let’s go back one slide and talk a little bit about Site Recovery Manager as well. And we’re going to cover this at a really high level too. But essentially, here’s what site recovery manager does.

We have this protected site and this recovery site. And if we’re running Site Recovery Manager, we’re worried about the sort of situation where we lose our entire protected site, right? So let’s say we’ve got replication going and all of my data is being replicated from the protected site to the recovery site. So we know that we have a current copy of our data at both locations. And that’s a good thing. We’re not going to have a lot of data loss if we do have this sort of disaster type scenario. What SRM does is it automates the disaster recovery response. So if our protected site fails, think about all of the things that need to happen. We’ve got all these VMs that now need to run at the recovery site. So those VMs need to get booted up on an ESXi host.

They might need their IP address changed. There might be database VMs or domain controllers that need to boot up first and then other components boot up in a certain order. After that, I might want to drop those VMs into different resource pools. There’s all kinds of little nuances that are going to happen as I spin up all of my VMs at that recovery site. That’s what SRM gives you is the ability to cut down that recovery time objective by automating all of that stuff that needs to happen when you recover from a disaster. And it also gives you the ability to test out your Dr plan, not intrusively without taking anything down to the protected site.

Okay, so in this lesson we learned about Vsphere replication and how it is a Vsphere based replication solution that is managed using the Vsphere web client. And we do have to deploy the VR appliance or Vs Fare replication appliance in order to configure this. It will send VR, Lightweight, Deltas, or essentially all of the changed blocks as frequently as we’ve defined in the recovery point objective. So as frequently as once every 15 minutes, or it can be as infrequently as once every 24 hours.

24. Fault Tolerance

In this video, I’ll explain fault tolerance and how it can be used to provide zero downtime protection for critical virtual machines. And that’s really what fault tolerance is all about. It’s about giving you 100% uptime with no data loss, no transaction loss for critical virtual machines by mirroring that virtual machine onto a secondary host. So there’s going to be multiple running instances for that virtual machine that ensures that they’re always going to be exactly identical. And there’s essentially what we call a hot standby. There’s another copy of this VM running on another host ready to take over at all times. So if a host fails, the primary VM will immediately fail over to the secondary VM, and then a new secondary will respond to reprotect that virtual machine just in case there’s another failure that occurs after that. And we can even place the secondary VM at a different data store to provide an additional level of protection. So let’s take a look at how this works.

Here’s my primary VM running on host ESXi One, and my Virtual machines files are located on this data store. We’ll call it data store. Here’s. Data store one. So I’ve got my Virtual Machine and my set of Virtual Machine files, and my VM is fine. It’s up and running, everything’s good. And then I go ahead and I create. Number one thing I have to create is a network, a fault tolerance logging network between those two ESXi hosts. And the purpose of this fault tolerance logging network is to basically track the state of my primary virtual machine and make sure that the secondary virtual machine is kept exactly the same.

So if I go into this primary VM and I open a console and I start moving my mouse around, the exact same thing is going to happen immediately in my secondary VM. That’s the purpose of this fault tolerance logging network is to make sure that the state of those virtual machines is kept exactly the same and same thing with those Virtual Machine files. So now I’ve got a primary and a secondary VM that are completely identical. And if the primary fails or if a host fails and the primary goes down, the secondary will take over immediately, right? So let’s talk about what happens when a host fails. So again, here’s my primary VM running on ESXi one. My secondary VM running on ESXi Two, and now I have my failure. ESXi One goes down and the primary VM goes down with it. Well, what’s going to happen at that point is the secondary instance on ESXi Two will immediately take over, will become the primary, and then to reproduce itself, a new secondary instance will be spawned on some other ESXi host. So now, even if ESXi Two fails, there’s still that level of protection there for that virtual machine.

Now, the only thing you have to kind of think about with fault tolerance is what if something happens at the guest OS level, right? So for example, let’s say that we have the Windows blue screen of death right? In our primary here. Something happens within Windows that creates a problem. Well, the bad news is fault tolerance is going to immediately replicate that change to the secondary virtual machine. So fault tolerance does not give us any protection from a failure within the guest operating system. And the main thing you want to bear in mind for fault tolerance is, number one, that it’s zero downtime. It’s meant for really important virtual machines that require 100% uptime. And it’s very resource intensive. So it’s not, like, high availability.

High Availability is designed for protecting entire clusters of hosts and protecting a lot of VMs. Right. With fault tolerance, we’re picking and choosing a few critical VMs and giving them this 100% uptime protection. So fault tolerance is not really meant for all virtual machines, right? Ha is kind of like your blanket protection for all VMs and then we’ll pick and choose certain critical VMs that require fault tolerance, right? So fault tolerance gives us 100% uptime, whereas High Availability requires virtual machines to boot up on other hosts and has downtime involved. Fault tolerance keeps a primary VM on one host and a secondary VM host on a different ESXi host than data store. And if there is a host failure that occurs, the primary VM immediately fails over to the secondary with no downtime. And then a new secondary will be respond to protect this virtual machine after failover.

25. Demo: Navigating the vSphere Web Client

In this video we’ll take a look at how to navigate the Vsphere Web client. And as you can see, I have logged into the Vsphere Web client here and I’m at my home screen and you may notice there are certain areas of my screen that are minimized. Now I can click on the username that I’ve logged in as here, the drop down next to it and I can reset to factory defaults, basically saying I want to see the Vsphere Web client exactly as it is normally set up. So I’ve probably made some changes over time and minimize certain areas of the screen to give myself more room. If I want to kind of see the default configuration, that’s my way to do that. And there’s a good reason that I had it set up that way. All of these different areas take up quite a bit of space and so as you’re working with the Visa Web client at certain times you may want to take those out of your view. So what we’re going to do is we’re going to go through each of these little areas and I’m actually going to unpin some of them as I cover them. And the first area is really straightforward.

These are all of our alarms. And right now you can see I have an alarm for virtual machine CPU usage, I have another alarm for the health status of Vcenter server and an expired license alarm. And what I can do is I can either acknowledge these alarms to basically say I’m working on these, so I’ll acknowledge this expired license alarm and now if I look at my new alarms, it won’t appear there, it’ll appear under acknowledged, basically giving me that nice warm and fuzzy feeling that somebody’s working on this. Or I can reset it to green and basically clear the alarm altogether. You can do that with any of these alarms. Now if it’s an ongoing problem like high CPU usage, that alarm will come back.

But right now I’m just going to reset all of my alarms to green and I am going to unpin the alarms screen. And what that will basically do is it’ll send it off to the side and if I now need to see my alarms, I can just jump in there and grab it. The next little window that’s important is the work in progress window. So let’s take a look at what that is. Let’s say I decide I want to go ahead and add another host to my Vcenter inventory, but then somebody interrupts me and comes into my office, asks me to look at something else.

I can click these two little triangles here and minimize that task over here to the work in progress area. And now I can go ahead and do anything else that I might want to do in the Vsphere Web climb. And if I ever want to go back to that task and finish it, I can simply click on it and wrap up what I was working on before. So that’s what the work in progress area is about. Down here at the bottom of the screen, we can see our recent tasks. This is basically all the stuff I’ve been doing. So if I decide, hey, I want to power off this virtual machine that will appear in a work in progress as it’s progressing, it’ll show me that. And then the task is now completed. It’ll show that there as well. And then up here at the top, we’ve got our little Navigator screen here. So I can go to the home screen. I can use this little clock to kind of go back in time and look at any of the other stuff that I’ve been up to.

And I’ve got my four familiar views right here that I’ve had with the Vsphere client forever, right? Hosts and clusters, VMs and templates, storage and networking. And then there’s a whole bunch of other features shown here in my Vsphere Web Client screen. Now, what I’m going to actually do here is just very briefly define a lot of these icons. And that’s something that you’re going to need to be able to do if you’re taking the VMware certified Associate exam. So a lot of this has actually already been covered in the lecture of this course, but let’s just take a couple of minutes and review some of the items that are shown here. First off, we’ve got content libraries.

A content library is a repository of things like templates, ISO images, vApps that can be shared across multiple Vcenter servers. So if I have multiple Vcenter instances and I want to have a consistent set of templates or ISO images, I can use a content library for that. Vsphere data protection is my virtual machine backup solution. I can create backup jobs for virtual machines. I can set up retention policies, and I can even do file and folder level restores. Vs fare replication is used to keep a current copy of data at a recovery site. So this is a disaster recovery type solution where as frequently as once every 15 minutes I can replicate a bunch of data from my primary site to a recovery site. And then we have a few other areas that we can look at here. We can look at our task console just to see what tasks we’ve completed, what tasks are currently ongoing. I can also look at my events screen to see if any problems have occurred, if I’ve had some health status changes or other issues that I need to dig into. And we’ve got the filter option up here at the top, right?

So if I want to filter based on a certain string, let’s say for my Rick Creechy demo VM, I can type in the word Rick Crete demo and filter and only show information related to that particular target. So that’s a quick, high level introduction to the Visa Web Client. Now, just always be aware you’ve got this little home icon up here that you can use to browse around the environment, and you can refresh what’s being displayed in the Visa Web Client right here. When you’re done, you can click on the little dropdown next to your username and log out, and that will bring you out of the Visa Web Client session.