Datastores are logical containers, analogous to file systems, that hide specifics of physical storage and provide a uniform model for storing virtual machine files. Datastores can also be used for storing ISO images, virtual machine templates, and floppy images.
Types of Datastores Depending on the storage you use, datastores can be of different types.
Understanding VMFS Datastores To store virtual disks, ESXi uses datastores. The datastores are logical containers that hide specifics of physical storage from virtual machines and provide a uniform model for storing the virtual machine files. The datastores that you deploy on block storage devices use the native vSphere Virtual Machine File System (VMFS) format. It is a special high-performance file system format that is optimized for storing virtual machines.
Upgrading VMFS Datastores ESXi uses different approaches to VMFS5 and VMFS3 upgrades.
Understanding Network File System Datastores An NFS client built into ESXi uses the Network File System (NFS) protocol over TCP/IP to access a designated NFS volume that is located on a NAS server. The ESXi host can mount the volume and use it for its storage needs. vSphere supports versions 3 and 4.1 of the NFS protocol.
Creating Datastores You use the New Datastore wizard to create your datastores. Depending on the type of your storage and storage needs, you can create a VMFS, NFS, or vVols datastore.
Managing Duplicate VMFS Datastores When a storage device contains a VMFS datastore copy, you can mount the datastore with the existing signature or assign a new signature.
Increase VMFS Datastore Capacity You can increase the capacity of a VMFS datastore. Additional capacity might be required when you add virtual machines to the datastore, or when the virtual machines running on the datastore require more space.
Enable or Disable Support for Clustered Virtual Disks on the VMFS6 Datastore If you plan to use a virtual disk in Windows Server Failover Clustering (WSFC) configurations, your VMFS6 datastore must support clustered virtual disks. Use the vSphere Client to enable the clustered disk support.
Administrative Operations for Datastores After creating datastores, you can perform several administrative operations on the datastores. Certain operations, such as renaming a datastore, are available for all types of datastores. Others apply to specific types of datastores.
Set Up Dynamic Disk Mirroring Typically, you cannot use LUN manager software on virtual machines to mirror virtual disks. However, if your Microsoft Windows virtual machines support dynamic disks, you can mirror virtual disks across two SAN LUNs. Mirroring helps you to protect the virtual machines from an unplanned storage device loss.
Collecting Diagnostic Information for ESXi Hosts on a VMFS Datastore During a host failure, ESXi must be able to save diagnostic information to a preconfigured location for diagnostic and technical support purposes.
Checking Metadata Consistency with VOMA Use vSphere On-disk Metadata Analyzer (VOMA) to identify and fix incidents of metadata corruption that affect file systems or underlying logical volumes.
Configuring VMFS Pointer Block Cache Pointer blocks, also called indirection blocks, are file system resources that contain addresses to VMFS file blocks. When you open a vmdk file on an ESXi host, pointer blocks related to that file are stored in the pointer block cache. The size of the pointer block cache is a configurable parameter.