> # Difference Between San Device Virtualization and FlexAttach Port Virtualization

> Table 13-1 describes the difference between SAN device virtualization (SDV) and FlexAttach port virtualization.

> Table 13-1 Difference Between SDV and FlexAttach Virtualization

> SAN Device Virtualization (SDV) | FlexAttach Virtualization
> --- | ---
> Facilitates target and disk management, and only facilitates disk and data migration. | Facilitates server management and has no restriction on the end devices used.
> WWN NAT and Fibre Channel ID (FC-ID) are allocated on the virtual device, both primary and secondary. | WWN and Network Address Transport (NAT) is allocated to host bus adapter (HBA).
> FC-ID rewrite on the switch indicates a rewrite-capable switch on the path. | No rewrite requirements.
> Configuration is distributed. This allows programming rewrites and connectivity anywhere. | Configuration distribution is not required for any of the interface-based configurations.
> Configuration is secured to device alias. | Does not require device alias for virtual pWWN.
> Does not allow automapping to the secondary device. | Allows automapping to the new HBA. Mapping process is manual for NPIV.

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