> # Comparing VSAN Versus Zone-Based QoS

> While you can configure both zone-based QoS and VSAN-based QoS configurations in the same switch, both configurations have significant differences. Table 11-1 highlights the differences between configuring QoS priorities based on VSANs versus zones.

> Table 11-1 QoS Configuration Differences
> VSAN-Based QoS | Zone-Based QoS
> --- | ---
> If you configure the active zone set on a given VSAN and also configure QoS parameters in any of the member zones, you cannot associate the policy map with the VSAN. | You cannot activate a zone set on a VSAN that already has a policy map associated.
> If the same flow is present in two class maps associated to a policy map, the QoS value of the class map attached first takes effect. | If the same flow is present in two zones in a given zone set with different QoS values, the higher QoS value is considered.
> — | During a zone merge, if the Cisco NX-OS software detects a mismatch for the QoS parameter, the link is isolated.
> Takes effect only when QoS is enabled. | Takes effect only when QoS is enabled.

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