Learn to differentiate between VMFS (Virtual Machine File System) and NFS (Network File System) storage solutions used to create VMware vSphere data stores. Also understand storage operations from the perspective of the VM.
- [Instructor] In this video, I will explain VMFS and NFS datastores, and also talk about the difference between these two stores' technologies. First, let's take a look at a VMFS Datastore on a Storage Array. Now, VMFS is VMware's own virtual machine file system. If we want to store VMs on disc, there must be a file system in place that the ESXi Host understands. So, in our slide, we see an ESXi Host that has access to some sort of storage array. It could be Fiber Channel, Fiber Channel over Ethernet, or IsCSI, and the host can see chunks of raw, unformatted disc space called LUNs.
Running on the ESXi Host are our virtual machines, and these virtual machines sit behind the layer of abstraction that the ESXi Host provides. This means that the virtual machines can't see the underlying physical storage hardware. So, any type of storage that we deploy kind of feels the same to our virtual machines. The ESXi Host is equipped with a storage adapter. This is some sort of adapter that allows the host to establish connectivity to the storage array.
Once connectivity is established to the storage array, we can use the vSphere Web Client to browse the available LUNs, and to create a VMFS-formated Datastore. And now, we have space that's suitable to store our virtual machines. So this file system is created by the ESXi Host, and if other hosts are connected to the storage array, they can also see and utilize this datastore. We can even boot our ESXi Hosts from Fiber Channel, Fiber Channel over Ethernet, and IsCSI Storage Arrays.
We can also create a VMFS Datastore on Direct-Attached Storage, or local storage. So, here we see an ESXi Host, and from the perspective of the virtual machine, nothing's really going to change here. It's still going to see, simply, discs. That's all the guest operating system sees. However, instead of using a storage array now, we're going to use Direct-Attached Storage, or local storage. Discs that are present right within our ESXi Host. And we can use the vSphere Web Client to create a datastore right on those local discs.
Now, this does have some drawbacks. Local storage doesn't support many vSphere features, like high availability, vMotion and DRS. NFS Datastores are very different from VMFS. Our ESXi Hosts cannot boot from an NFS device. Here, we see our ESXi Host, and a Network-Attached Storage Device. There is no VMFS involved here. The NFS Device owns and operates the file system.
And the ESXi Host simply acts as a folder that has been shared by the NFS device, and we can then create virtual machine files within that folder. So here we see our virtual machine again, and the virtual machine has no idea if we're using NFS, or IsCSI, or Fiber Channel or local storage. We'll use a standard TCPIP Network to connect to an NFS Device, so we'll need to establish a virtual switch with physical adapters assigned to it on our ESXi Host.
And once we've established connectivity to the NFS Device, we can go ahead and create a datastore on it. There's no formatting, no VMFS involved here. However, the NFS Datastores do support many of the same features as VMFS. They support high availability, fault tolerance, DRS, and vMotion. There are two key features that are not supported, and those are Raw Device Mappings and Boot from Sam.
Note: This course maps to the Configure and Administer Advanced vSphere 6.x Storage domain from the VCP6-DCV exam blueprint. Learn more about the exam objectives at VMware's site.
- Comparing VMFS (Virtual Machine File System) and NFS (Network File System)
- Working with Fibre Channel and FCoE
- Configuring iSCSI storage and authentication
- Working with block storage and VMFS
- Managing storage filters
- Using vSphere storage APIs
- Sharing virtual disks
- Configuring NFS storage
- Using vSphere Virtual Volumes
- Configuring VSAN data stores
- Configuring SIOC data stores