You are creating a virtual disk for a VMware VM running on vSphere 6.

When creating a virtual disk for a VMware VM that will reside on a datastore provisioned from an XtremIO volume, it is generally recommended to use Thick Provisioned, Eager Zeroed disks for optimal performance and capacity usage. Here’s why:

Thick Provisioned, Eager Zeroed (OC): This type of disk allocation pre-allocates the entire size of the disk and zeroes out all the blocks at the time of creation.This can lead to better performance because all the space is allocated and ready for use, and there is no overhead associated with zeroing out blocks during write operations1.

Thick Provisioned, Lazy Zero (OA): While this also pre-allocates the entire disk size, it does not zero out the blocks until they are first written to.This can lead to potential performance degradation compared to Eager Zeroed disks when the blocks are zeroed on demand1.

Thin Provisioned (OB): Thin provisioning allocates disk space on demand rather than pre-allocating the entire disk size.While this can be more efficient in terms of capacity usage, it may not provide the same level of performance as Thick Provisioned, Eager Zeroed disks, especially in high I/O environments1.

Raw Device Mappings (OD): RDM allows a VM to directly access a LUN on the SAN.This is typically used for specific use cases that require direct access to the physical storage device and is not generally necessary for standard VM deployments1.

In summary, for ensuring proper performance and capacity usage, Thick Provisioned, Eager Zeroed (OC) is the recommended way to present the disk to the guest for a VMware VM running on vSphere 6.5 with an XtremIO volume1.