User`s guide

174 XgOS User’s Guide • September 2014
Optional LUN Masking: No Report LUN
Interception
When a host (Linux or Windows) issues a SCSI report LUNs, the chassis filters the
response based on what is in the Oracle Fabric Interconnect database. If LUN
masking changes in an array and a host issues a report LUNs, the new LUN will not
be available to the host until a set vhba rescan command is run on the Oracle
Fabric Interconnect. In some cases, this approach goes against customer expectations
and breaks the existing model.
Use the -no-lun-masking feature to disable the LUN masking so that if you
choose to do LUN masking on arrays, rescans on the Oracle Fabric Interconnect are
not required. Specifically the -no-lun-masking feature disables the “report luns”
interception and allows all new LUN/target information to pass through directly to
SCSI. When SCSI issues the report luns command, the request will pass through
the Oracle Fabric Interconnect’s IOP and discover the disk array’s new LUN/target
information.
When a vHBA is created, LUN masking is enabled by default. An administrator
must use –no-lun-masking to disable it. The –no-lun-masking flag can be
specified only during the creation of a vHBA and cannot be changed throughout the
lifetime of this vHBA. After specifying this flag while creating a vHBA, the CLI will
also prevent you from assigning any LUN mask to this vHBA.
Note – No Report LUN Interception is the default when a vHBA is created.