NFS Storage Integration on ESX

Introduction

Abiquo cannot create a volume directly on an NFS share mounted on a VMware hypervisor. Therefore, the NFS storage feature has been implemented as follows:

1. Abiquo mounts the new NFS share dynamically when you deploy and creates the required filesystem structure
2. Abiquo creates:
   
   1. VMDK disk on the hypervisor datastore
      
      • named NFSDISK-<UUID>.vmdk
      • very small file size
      • contains a pointer to a disk on the NFS share
   • Disk on the NFS share
     
     1. Raw
     2. Thin provisioned
     3. Named with a UUID

The following screenshot shows the contents of the two VMDK disks for a persistent virtual machine (stored on the NFS share) with an NFS volume attached.

ESXi NFS Storage Considerations

When you are accessing ESXi directly (e.g. through vSphere client), consider the points in this section.

View the File

The free space in the vmFolder (the datastore where the VM is deployed) is not affected by the size of NFS disks. If you browse the datastore, vSphere client will show you the NFSDISK-xxxx of size X, which is because the browse reads the .vmdk and shows the reported size. But this doesn't increment the usage in the local datastore because it only links to a file on another datastore.

If you browse the virtual disks, you will see the NFS volumes.

The following screenshot shows two NFS external volumes of approximately 100 MB.

View the Disk

When you view the disk on the Hardware tab, ESXi will show the following disk information.

• When the disk is created, before a filesystem is created
  • Thin provisioned
• Once the disk has a filesystem
  • Thick provisioned
  • Capacity is the maximum size of filesystem
    
    • This does not show the used size

Resize NFS Disks

Disks on NFS volumes can only be resized using Abiquo.

You cannot resize the NFS disk directly through ESXi.

If you try to modify the disk size using the vSphere client, you will receive the message:  "Insufficient disk space on datastore".

This message indicates that the disk resize operation is not valid.