Data ONTAP allows you to create and manage a separate set of iSCSI LUNs and igroups on each vFiler unit. As the vFiler unit or hosting storage system administrator, you need to be aware of certain considerations.
For a host importing LUNs, a vFiler unit looks and behaves as a storage system. Administrators of those hosts need not be aware that the LUN resides on a storage unit owned by a vFiler unit.
You must remember the following points when you manage LUNs on a storage system on which MultiStore is enabled:
- You must create and manage LUNs from the vFiler unit that owns the storage containing the LUNs.
- A vFiler unit is aware only of those LUNs that are in the storage units owned by the vFiler unit.
When executed on a vFiler unit, the lun show command displays only that vFiler unit’s LUNs.
- Ownership of LUNs changes with the ownership of the storage unit that contains the LUNs.
- LUNs must be unmapped before you can move the storage unit containing the LUNs.
Therefore, you must unmap all affected LUNs before performing any of the following tasks:
- Assigning storage that contains LUNs to a vFiler unit, either when you create the vFiler unit or later
- Destroying a vFiler unit that owns storage containing LUNs
- Moving storage that contains LUNs from one vFiler unit to another, or between a vFiler unit and the hosting storage system
If you try to move a storage unit without unmapping the LUNs it contains, the operation fails. For instructions on unmapping LUNs, see the Data ONTAP SAN Administration Guide for 7-Mode.
Note: You do not have to unmap LUNs when you migrate a vFiler unit or replace it for disaster recovery purposes.
- igroups are owned by the vFiler unit on which they are created.
- Like LUNs, a vFiler unit is aware only of those igroups that it owns.
When executed on a vFiler unit, the igroup show command displays only that vFiler unit’s igroups.
- LUNs must be mapped to igroups owned by the vFiler unit that owns the LUNs.
- Each vFiler unit has its own namespace for LUNs and igroups:
- igroups on different vFiler units can have the same initiator.
- LUNs on different vFiler units can have the same LUN ID.
- When you migrate a vFiler unit or replicate it for disaster recovery purposes, LUNs owned by the vFiler unit are also migrated or replicated, along with their maps, igroups, and iSCSI configuration (the node names and the state of the iSCSI service). However, iSCSI authentication is not migrated or replicated.