HP Cisco Nexus 5000 Cisco MDS 9000 Family CLI Configuration Guide - Release 4. - Page 540

SDV Requirements and Guidelines Chapter 21 SAN Device Virtualization Send documentation comments to [email protected] A blank commit is a commit operation that does not contain configuration changes, and enforces the SDV configuration of the committing switch fabric-wide. A blank commit operation resolves merge conflicts by pushing the configuration from the committing switch throughout the fabric, which reinitializes the conflicting virtual devices. Exercise caution while performing this operation, as it can easily take some virtual devices offline. Merge failures resulting from a pWWN conflict can cause a failure with the device alias as well. A blank commit operation on a merge-failed VSAN within SDV should resolve the merge failure in the device alias. You can avoid merge conflicts due to configuration mismatch by ensuring that: • The pWWN and device alias entries for a virtual device are identical (in terms of primary and secondary). • There are no virtual device name conflicts across VSANs in fabrics. SDV Requirements and Guidelines Be aware of the following requirements and guidelines as you plan and configure SDV: • SDV should be enabled on switches where devices that are part of SDV zones are connected. • SDV does not work for devices connected to non-MDS switches. • Broadcast zoning is not supported for a zone with a virtual device. • IVR and SDV cannot be used for the same device. In other words, a SDV-virtualized device cannot be part of a IVR zone or zoneset. • Virtual device names should be unique across VSANs because they are registered with the device alias server, which is unaware of VSANs. For example, if you have enabled SDV and have registered a name, vt1 in both VSAN 1 and VSAN 2, then the device alias server cannot store both entries because they have the same name. • You cannot specify the same primary device for different virtual devices. • SDV does not work with soft zoning (Soft zoning means that zoning restrictions are applied only during interaction between the name server and the end device. If an end device somehow knows the FC ID of a device outside its zone, it can access that device), nor does it work with the zone default-zone permit vsan operation (which would otherwise permit or deny traffic to members in the default zone). • If devices are not already zoned with the initiators, then you can configure SDV virtual device zones with no negative impact. If they are already zoned, then zoning changes are required. • The real device-virtual device zone cannot coexist with the real device-real device zone. If the real devices are not already zoned together, then you can configure the real device-virtual device zone with no negative impact. If these devices are already zoned, then adding the real device-virtual device zone may cause the zone activation to fail. If this occurs, then you must delete one of the zones before activation. For example, a user attempts to create a configuration with zone A, which consists of I, the initiator, and T, the target (I,T), and zone B, which consists of a virtual initiator, VI, and real target, T (zone VI, T). Such a configuration would fail. Likewise, an attempt to configure zone C, which consists of an initiator, I, and target T, with zone D, which consists of an initiator, I, and virtual target, VT (zone I, VT), would also fail. 21-12 Cisco MDS 9000 Family CLI Configuration Guide OL-18084-01, Cisco MDS NX-OS Release 4.x