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11. VMFS vs. NFS

In this video, we'll break down the two primary types of data stores offered on Vsphere: VMFS and NFS. Let's start by taking a look at a VMFS data store. So there are many different types of stores and arrays that you could potentially purchase. In this particular slide, we see an Iscuzzy storage array that's been deployed. Now there are a lot of other options out there. There's a fibre channel. Fiber Channel over Ethernet And basically, the big difference between those different options is the type of network that they use. In this case, let's assume that it's an iSCSI storage array, which is a VMFS storage solution. Fiber channel and fibre channel over Ethernet are also going to utilise VMFS data stores. So for the moment, let's just get rid of our ESXi host here on the lefthand side of the screen, and let's focus purely on the storage array itself. So this is an Escazi storage array, and you can see here some of the key characteristics. Our host is going to communicate with the storage array over an Ethernet network. And the storage array is equipped with two storage processors.

We've got our nice little redundant connections here just in case one of those Ethernet switches fails or the storage processor fails. And just think of the storage processors. Those are like the brains of the operation. And this is the same if you're dealing with Icecuzzy, Fiber Channel, or Fiber Channel over Ethernet. What's really different about those three different types of switches is the type that we're going to use here. using fibre channel We're going to use a fibre-channel switch fabric. with fibre over Ethernet. We're going to use an Ethernet switch. And, as with Icecozy, we'll be using an Ethernet switch. Then there's the storage array itself, which is on the right. So the storage processors are kind of like the brains of the storage array. They also provide connectivity. And then we've got a shelf of discs called our aggregate. That's all the physical space that the storage ray is equipped with.

And we're breaking down all of that physical space into smaller chunks called LUNs, or logical unit numbers. And that's all that a loan is: a chunk of space on a storage array. So now that we've kind of got the storage components figured out here, we can see that ESXihost also connects up to these Ethernet switches. Or maybe it's Fiber Channel, and they'll connect to the Fiber Channel switch fabric. It doesn't matter in either case. It's kind of the same concept here. And so now that we've got an ESXi host with a communications channel where it can speak to the storage array and we have these LUNs that are created on the storage array, we're in a position where we can actually go ahead and start creating some VMFS data stores. And the first step of that process is a significant one. We have to discover targets.

And for the time being, I'll just concentrate on Isczzy. So here's my ESXi host, and I want to create a data store that is properly formatted and has the correct file system that's going to allow me to store virtual machines. and right now I can't do that. These lungs are raw, unformatted disc space chunks. These are just chunks of space. Think of them like a physical disc that you just pulled out of the box. There's nothing on them. There's no file system present. I can't store anything on these discs just yet. same thing with lungs. They have to be formatted before they can be used. So with Iscuzzy, we're going to use a method called automatic discovery or dynamic discovery. And the first step is to configure the host with the target IP address. So we're going to tell our ESXi host, "Okay, if you want to discover the available ones, this is the address that you should query." You should query 10-10, or, I'm sorry, 10-10-0, which is the IP address of our storage processor, at which point we can perform a rescan on our ESXi host and have it query that storage processor's database. It generates what we call "send targets" requests and storage. The processor will receive that query, and it will respond with a list of all of the available ones that it has.

Now, my ESXi host knows about the essentially blank discs that it can use, right? The big chunks of raw, unformatted disc space There are three of them. We can now select one of those lungs and create a data store on it. And when a VMFS data store is created, what essentially happens is this. The space on this loan is going to get formatted with the VMFS file system, and it is now going to be presented to my ESXi host as a data store. We'll call it Data Store One. And now I can start storing virtual machines on it because it has now been formatted with the VMFS file system and is now suitable storage for my virtual machines. So when you think about VMFS, kind of think about the concept that we have lungs. With VMFS. We have lungs. Lungs are unformatted discs that must be formatted with the VMFS file system. This is very different from the way that NFS works. NFS is a whole different ballgame.

And so with VMFS, let me jump back a slide. With VMFS, these lungs behave very much as if they were physical disks. I can even have an ESXi host with no local storage, and it can boot from one of these LUNs. So we can even do stuff like that. When it comes to VMFS, NFS is very different, right? I cannot boot a host from an NFS share. That's not possible. There's no VMFS involved. When we start talking about NFS, there's no VMFS; there's no special file system. The NFS device has its own file system. It operates its own file system. And then ESXihost simply accesses the shared folder. We call this an NFS export. There's going to be some folder that we create on this NFS device or network attached storage device, whichever you want to call it, that we are going to present very similarly to a shared folder. We're going to present that to our ESXi host. The ESXi host doesn't have to format it. There's no file system to be created.

And aside from the ability to boot from Sam, there are really not a lot of feature differences between an NFS data store and a VMFS data store. Really, the only two things that NFS does not support—or rather, the only two really key things—are the ability to boot a host from Sam and the ability to create a raw device mapping. I can't give a virtual machine direct access to a loan because I don't have any lungs. So raw device mappings are not supported. Right. So let's take a look at how my ESXi hosts actually connect to an NFS data store. On the left, we can see a virtual machine with a virtual scuzzy controller. And just like we talked about in the storage virtualization video, my guest operating system, Windows in this case, is going to generate scuzzy commands. And as they flow out of Windows, they're going to hit my virtual SCSI controller, and from there, they're going to hit a storage adapter. And in this case, the storage adapter is pointing towards this NFS data store that we've mapped.

So the scuzzy commands are actually going to be pushed over to a VM kernel port and transmitted across the network to the IP address of this NFS system. And the data store that we created was created in a specific folder, and ESXihost has root access to that folder. So now, as my virtual machine generates scuzzy commands, they flow out. They're prepared for a transmission over the network. They hit a VM kernel port, flow over an Ethernet network, hit the interface on the NFS system, and are redirected to the VMDK for that virtual machine that exists on this NFS storage system. So again, really quickly, just a review with VMFS: we want to think of VMFS as having LUN chunks of raw disc space that must be formatted, and we can boot our hosts from those lungs. With NFS, the file system is already in place. There's no formatting required. The file system is already there, and we're just basically accessing a shared folder that was created on that file system.

So, if you ever create an NFS data store, you'll notice that they don't take very long to create because there's no formatting, zeroing, or anything like that. It's just done. You mount your shared folder, and you're finished. So in this lesson, we learned about VMFS. We learned that iCoy fibre channel and fibre channel over Ethernet storage rays utilise VMWS and are within the storage array. There are these raw, unformatted lungs that the ESXi hosts must format with the VMFS filesystem, whereas NFS has its own file system independent of ESXi and no formatting is required.

12. Storage DRS

In this video, we'll learn about storage. distributed resource scheduler, or storage DRS. Storage DRS is based on data store clustering. So we've already learned a little bit about ESXi host clusters and how they can be used for things like high availability and DRS. A datastore cluster is very similar. It's just a logical grouping of data stores. And these data stores may contain files for many virtual machines. And as we add virtual machines, the data stores may potentially become unbalanced. So, for example, maybe some really storage-intensive workloads have been placed on Data Store One. Or maybe Data Store Two is running low on space. Storage DRS can automate load balancing across these data stores, and it uses Storage V Motion. So just as a quick refresher, here we see an ESXi host with a virtual machine running on ESXi host one. If I want to carry out a Storage V Motion, what I'm doing is taking all of the files that belong to that virtual machine and migrating them from one data store to another with no downtime. That's what storage vs. motion is. So the virtual machine continues to run on the same host, but all of the underlying files are being moved from one storage location to another. That's what storage vs. motion is. Storage v. Motion is the underlying technology behind Storage DRS. Storage DRS will therefore automatically move virtual machines around in order to balance capacity, usage, and latency. So, for example, if Data Store One is getting really full or if it has a lot of storage-intensive virtual machines that are generating a lot of traffic, it may start moving virtual machines to other datastores to even out that workload. Now, there may be certain circumstances in which this can create some problems. So, for example, here we see two virtual machines: domain controller one and domain controller two. And these are redundant. We don't want both of our domain controllers to be down at any time, no matter what. But if we turn over control to Storage DRS, it could potentially move those domain controllers to the same data store. And if that data store fails, we've now lost both of our domain controllers. So we can use something called an "anti-infinity rule" to ensure that those domain controllers are kept separate. We can even configure affinity or anti-infinity rules for individual virtual machine discs to keep them separate or together. But you probably don't have to do a whole lot of that. By default, if you create a virtual machine with multiple disks, all discs will be stored on the same data store. So one of the handy things about creating a data store cluster is that you can put the data store into maintenance mode. So let's say the data store on the far left is on one storage device, and the other two data stores are on other storage devices. And maybe I need to take down a storage device, like maybe a fibre channel storage array, to do some sort of patching. Well, I can put that data store in maintenance mode. And what Storage DRS will do is automatically evacuate that data store for me with no service interruption. So now I can take that datastore on the left down, reboot my fiberchannel storage array, perform any necessary maintenance, and when it returns, that storage load will be rebalanced in accordance with Storage DRS recommendations. So it definitely helps with things like maintenance. The first step is to establish a data store cluster.

Now, you have to bear in mind that virtual machines are going to be moving around from one data store to another. So you want data stores that are going to act similarly, and that means data stores with similar performance characteristics and data stores with similar policies. For example, if one data store is replicated, we don't want a virtual machine automatically moving off of it to a data store that is not replicated. We can't mix NFS and VMFS data stores in a cluster, and we want to make sure that any shared storage within that cluster is available to as many hosts as possible.

Now, when we're setting up a storage DRS cluster, it's very similar to a DRS cluster for our hosts in that we can choose the level of automation. In manual mode, when I create a storage DRScluster, it's not going to do anything automatically. When it's going to do something, simply provide me with recommendations. Say this virtual machine should move from this data store to this data store. That's going to give me the option of deciding whether or not I want to carry out those recommendations. In partially automated mode, when we create a new virtual machine, we'll create it on a cluster. When we create a virtual disk, for example, we'll just pick the cluster, and in partially automated mode, Storage DRS will pick the optimal data store for that virtual disk. So in partially automated mode, we're kind of halfway there.

Storage DRS isn't going to automatically move anything anywhere. But when we're creating a new virtual machine, new virtual disc storage will decide where to put it. And then finally, we have a fully automated mode where our Storage DRS cluster will automatically use Storage V motion to migrate virtual machines from one data store to another. Again, for the purposes of load balancing capacity and latency, So in this lesson, we learned about some of the following topics: We definitely gave you a very concise description of Storage DRS. Again, I would recommend some of the more-in-depth classes if you want to learn more.

We've got the Vsfair Foundation course coming out soon, and we'll also be releasing a Vsfair Professional level course as well on Udemy, so all of those courses will take you much deeper into some of these features. So anyways, in reviewing this lesson, we learned about the following topics: We can have multiple data stores associated with a data store cluster, and then we can monitor space usage. and I O latency across that data storecluster, and make recommendations similar to the DRS we use with our hosts. We can implement these suggestions and use Storage V Motion to move virtual machines around. We can always add more data stores to a data store cluster as we need to. And again, the underlying mechanism for these moves is storage versus motion.

13. Storage I/O Control

In this video, we'll learn about storage IO control and how it can be used to prioritise storage traffic for certain virtual machines. Storage IO Control, then, provides storage prioritization. And consider storage I/O operations to be either reads or writes. Any type of storage command can be sent over a network. And what Storage IO Control does is use shares, reservations, and limits to control and prioritise certain VMs over others. It will monitor the latency of data stores to determine when to actually enforce this prioritization. And when poor performance is detected, storage outcontrol will be engaged, which will start to throttle back the less important virtual machines.

We can also use the Storage IO Control I O injector to determine how fast a data store can be so that we can more intelligently define some of these thresholds for when Storage IO Control should be invoked. Fiber channel, iSCSI, and NFS storage all support storage IO control, but virtual storage does not. So let's take a look at how storage I/O control works. Storage auto control, at its most basic, is simply sharing, limiting, and making reservations – the same resource controls we've seen in our lessons on resource pools, but for storage bandwidth. So if we have a situation where storage contention arises, we're going to pick and choose certain virtual machines to prioritize.

For example, here we've got this ESXi host on the left, and the ESXi host is connected to a data store on, say, a fibre channel storage array. And we know that the maximum amount of IOPS that could be pushed to this data store at any time is 3000. We can also simply identify a latency threshold. So we could say, "Hey, if latency exceeds 20 milliseconds, start kicking into storage IO control, and here's what's going to happen." We've got these two VMs, and both of these VMs have their virtual discs located on this data store. VM one has 500 shares, and VM two has 1000 shares. That is, if a contention problem arises, VM one will receive half the storage bandwidth that VM two does. So essentially, VM One can only push half the IOPS that VM Two can. Now, the beauty of shares is that, under normal operating circumstances, this is actually not enforced.

Shares are only enforced if a certain latency threshold is met. So when we start to have contention, that's when the share structure actually gets enforced. And hopefully the real goal here is to avoid this latency and this contention altogether by properly load balancing our data stores and by purchasing storage devices that can handle the required workload. So we could load balance our data stores using Storage DRS, which we learned about in the last video, and Storage I/O Control and Storage DRS are definitely complementary solutions. I kind of think of it this way. Storage.IO management is analogous to aspirin. When you get a headache, you can take aspirin, which will make you feel a little bit better but not actually attack the root cause of your headache. If you could potentially change whatever is giving you a headache and get rid of that, that's kind of like Storage DRS, right?

That's preventing the problem before it occurs. So what Storage DRS is going to do is monitor latency across a cluster of data stores, and if latency starts to get too high, it will use Storage Vmotion to start moving virtual machines around from one data store to another. And by balancing out that workload, hopefully we won't even need to invoke Storage Audio Control. Hopefully, the latency can be avoided altogether. Okay, so in review, storage idle control is used to prioritise storage commands over our network. We can configure shares, limits, and reservations, and they're only enforced when poor performance is detected. Or we can use the I/O injector to determine the maximum throughput of a data store. Storage out of control is supported on fibre channel ISGSY and NFS storage. And ideally, we can prevent the problem altogether by properly balancing our data stores. And a good way to automatically do that is to create a data store cluster and configure storage HDRs.

14. Virtual SAN

In this video, I'll introduce you to VMware's Virtual San, or vSAN, product and how you can use it to create a shared data store using local storage. Virtual Sand allows you to use local storage inside your ESXi hosts and to use that local storage to provide many of the features that typically require shared storage, such as high availability, V Motion, and DRS. Virtual Sand is going to be configured on a cluster of ESXi hosts.

And what we'll do is install local storage on our hosts and combine it in the form of disc groups. And those disc groups will combine to form a large shared data store that is going to be accessible to all of the hosts in the cluster. We'll even have high-speed solid-state drives that will act as a right buffer and a read cache to improve the performance of virtual machines. So let's take a look at how Virtual San works. In this scenario, we have a cluster of three ESXi hosts with some local hard disc drives and a couple of solid-state drives installed on each. In this case, this is what we refer to as a "hybrid configuration" in virtual sand. And with a hybrid configuration, here's how it works: The hard disc drives provide capacity.

This is where our data is persistently stored on these hard disc drives, and that's their purpose: to provide that kind of persistent storage of our data. Solid state drives, on the other hand, will serve as a read cache and a right buffer in SSD devices. And the goal is to have most of the read and write operations performed on SSD so that the entire cluster gets SSD-type performance. So in this scenario, we actually have four disc groups.

Each disc group is going to be made up of one SSD and then a group of capacity devices behind that SSD. So essentially, what we're doing is taking this storage hardware that we've installed locally on the ESXi hosts and grouping these ESXi hosts together in a cluster. And then we're combining all of that local storage to create this one big shared datastore called our Virtual Sand Data Store. And what we're doing is creating a shared datastore that is accessible to all of these ESXi hosts.

So, for example, let's say that you have a virtual machine that happens to be running on host ESXi Three. So here's my VM, right? I've got a VM that's running on host ESXi Three, and I want to move it to host ESXi Two. Well, because this data store is shared by all three of these hosts and is accessible to all three of these hosts, let's say that this virtual machine's VMDK just happens to be located here on host One.

I can now vote in that virtual booth. It doesn't matter which host the virtual machines' files are actually located on because all of the storage is accessible to all of the hosts in that cluster. So now we've got many of the advantages of a traditional storage array when it comes to shared storage and feature availability, but we didn't actually have to invest in a hardware storage array to make it happen. And really, the fundamental element that makes all of this work is a high-speed network running between these hosts.

So what we'll do is define an aVM kernel port on each host that is going to pass storage traffic around, right? So, for example, if I've got a virtual machine here on ESXi 1, when it puts out those storage commands, they're going to hit a VM kernel port, and they will be directed over my virtual SAN network to whichever host that VMDK happens to reside on. So now my VM can move all over the place within this cluster. I can V-motion it wherever I want.

I can turn on DRS and have that VM move around. And this high-speed virtual storage network that I've created will be used to carry all of that storage traffic. And the other critical component of virtual storage—the piece that really makes it work fast—is this read cache and write buffer that we are going to establish using SSD. So, if I have a host with a disc group on it, a flash device SSD will be part of that disc group. And when data is read, hopefully it will be read from that SSD layer. So 70% of this SSD on each host is going to be allocated as a read cache.

And the read cache contains all of my most frequently read data. And when the data is read from my read cache, the latency is very low because it's SSD. It's much faster than a traditional hard drive.

Assume that virtual machine one on our far left here in the purple block needs to read some data from disk, and that the read request flows out of the virtual machine. And in this case, it just so happens to be some frequently utilised data that was contained in the read cache.

So we can see here that the result is very fast, right? The read operation happens very quickly. The SSD provides the data really quickly, and the read operation is very, very fast. Let's say now that the virtual machine needs to read some data that is much less frequently accessed—some data that it doesn't usually need. Well, that date is going to need to be retrieved from the hard disc drive because it's not some of that high-value data stored in cash. And so those read operations are going to be much slower.

So by putting the most valuable and most frequently accessed data on SSD and maintaining a copy of that data there, most of our read requests should hit SSD, and it should give us SSD-quality read performance. The same is true for writing. 30% of the SSD is going to be allocated as a write buffer. So when my virtual machine needs to write some sort of data, it's going to be written to the SSD.

So here my virtual machine has some writes that it needs to perform, and those are going to be performed on SSD. And then, after the fact, the SSD will actually write that data to the long-term persistent storage of my hard disc drives. So as far as my VM is concerned, every write is happening at SSD speed. And then, after the fact, this process is transparent to the VM.

Those rights are actually pushed into that persistent storage. So that's just a brief introduction to the Virtual Sam product. And again, as a quick review, virtual Sam is configured on a cluster of ESXi hosts and can leverage local storage to provide shared storage.

The local storage is in the form of disc groups, which have SSD devices as read and write buffers. And then we have disc groups that include, of course, SSDs with recast and write buffers and also some sort of persistent storage behind them. And we have to have that fast, high-speed network as well to interconnect those ESXi hosts so that our storage commands are completed.

15. Virtual Volumes

In this video, we'll introduce virtual volumes. Virtual volumes are really the next generation of V-Surf storage. We've already spent some time learning about the MFS datastores and the NFS datastores and things like that. and virtual Sam Virtual volumes are kind of the next step in the evolution of storage. But the other nice thing about them is that they support a lot of the existing storage architecture that already exists. So, for example, virtual volumes support common storage networks like Fiber Channel, Iscosy, and NFS.

But the biggest difference is that our virtual machine objects are actually exposed to the storage array. Let's kind of think about the way things are right now without virtual volumes. What we've got are data stores. We've got these data stores, and here's our data store. And their data store is formatted with VMFS. So here's a VMFS data store. Well, when you take a data store and format it with VMFS, you're creating a file system on that data store that the storage array does not understand. The storage array is not able to dig inside a VMFS data store and view individual virtual machine objects.

And that's the biggest difference between virtual volumes and the traditional lawn. Furthermore, the VMFS architecture allows us to manage individual virtual machine objects at the storage array level. This makes things like cloning and snapshots very different than they've traditionally been with a VMFS data store. So with a traditional data store architecture, what we have are logical unit numbers. We're going to have these LUNs, and on those LUNs, we're going to create VMFS data stores. So here we see two lungs, and for each lung, we've created a data store. And then we can store all of our virtual machine objects within those data stores. And what the loan has typically provided is basically a container where all of those virtual machine files will be head rephrase. And what the lawn has typically provided is a storage container where all of those virtual machine files will be located.

Now, with Vvalls, the concepts of alawn and data store go away. So with Vaults, what we're going to do is create a new object called a storage container, and all of our Vaults or virtual volumes are going to be stored in this storage container. And the storage container doesn't have the traditional limitations of a locker. The only restriction is the actual physical storage capacity of the array. So do data stores still exist? Well, technically, yes, they do. But the data store is purely there for functions like high-availability data stores and things like that. What's really going on now is that we've got this one big storage container on the storage array, and the storage array has visibility over all of the individual virtual machine objects that are contained within that storage container.

So our storage container is where all of our virtual volumes exist. And as a virtual machine, it needs to send storage commands to its virtual disks. For example, we have something called the protocol endpoint that basically handles all the traffic. Our host doesn't really care about the storage container. It doesn't care how big or small it is. It doesn't care how many of them there are. There's going to simply be this protocol endpoint that will serve as an interface to the storage container. And so when my virtual machine issues ascuzzy command, the scuzzy command, just like always, will flow out of the virtual scuzzy controller of the VM and the ESXi host. The hypervisor will send it to the appropriate storage adapter through the protocol endpoint, and the database will be written to that individual virtual volume.

So those are some of the underlying mechanisms involved with virtual volumes. Now, in terms of what advantages it provides, Let's say that you need to clone a virtual machine. So we have this virtual machine, and the V-drive for the virtual machine is here, and we need to clone it.

Well, rather than handling the cloning operation at the ESXi host level, we can handle it at the storage container level and at the storage array, because the storage array can see all of these individual Vaults, and that's much more efficient. Let's think about a cloning operation where the host is handling it well. What's going to happen in that scenario is that all of this virtual machine's data is going to have to get pulled into the host, and then a copy of it all has to get pushed back to the storage array. That's the way that cloning has traditionally been performed.

What if, instead of this traditional method, if we wanted to perform a cloning operation, maybe Vcenter could simply send a command to the storage array and tell the storage array, "Hey, this virtual volume needs to be cloned." This virtual volume needs to be snapshotted, and then the storage array itself handles that workload without having to transmit all of that data over the storage network, right? We don't need that. We can offload those tasks to the storage arrangement. So there are huge efficiencies with virtual volumes, and that's why it's kind of the push toward the next generation of storage. Now, these are not going to displace traditional VMFS data stores anytime within the next couple of years, but eventually, the percentage of virtual volumes backed by storage devices will continue to grow.

VMware 1V0-701 practice test questions and answers, training course, study guide are uploaded in ETE Files format by real users. Study and Pass 1V0-701 VMware Certified Associate - Digital Business Transformation (VCA-DBT) certification exam dumps & practice test questions and answers are to help students.