User`s guide

306 Implementing an Open IBM SAN
Once completed, select Apply Changes and then Close. The host system may
now have to be restarted or some other method used to rescan the bus for the
host to detect that it now has access to new devices.
Any combination is allowed, so if the same LUN is to be shared by two different
hosts, a check mark for that LUN must be set for both. If this is the case, the host
systems must have a device sharing software installed to control access to the
disk device for data integrity.
As each Fibre Channel port can support up to 8 eight different hosts, there can
be up to 48 hosts attached to the SAN Data Gateway. They can all share the
same four SCSI channels. By using the Virtual Private SAN feature, you can
ensure that only the LUNs you desire a certain host to use will be accessed and
that no other host will access them.
4.5.3 Combining Zoning and Virtual Private SAN
If Virtual Private SAN is enabled and LUNs have been allocated to specific hosts,
then zoning is not necessary or required. The Channel Zoning window can
remain at the default settings with all Fibre Channel ports accessing all SCSI
channels.
However, they can work in combination to add an extra level of control and
security. If zoning is added, then VPS can only control the LUNs that are included
in its access zone. Figure 4-39 shows a zoned SAN Data Gateway.
Figure 4-39 Combining channel zoning and VPS