Host mapping vs. channel zoning – Dell PowerVault ML6000 User Manual
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Chapter 5 Configuring Your Library
Working With FC I/O Blades
Dell PowerVault ML6000 User’s Guide
117
map the controller device to a different LUN if an application typically
expects to see a media changer device (partition) or tape drive at LUN 0.
LUNs can also be mapped to be accessible by specific host server World
Wide Port Name (WWPN). Mapping a LUN to a specific WWPN can be
used instead of channel zoning to control device visibility. Mapping a
LUN to more than one WWPN may be useful for creating redundant
paths to a media changer device (partition), tape drive, or controller
device. LUNs will need to be mapped to each WWPN for host servers
that use multiple ports (e.g., multi-ported HBAs or multiple HBAs) if
access is desired via all the host server ports (e.g., a LUN would need to
be mapped to both WWPNs of a server that uses a dual-port HBA).
LUN masking is a complementary concept to host mapping in that LUNs
that are mapped to specific host server WWPNs are hidden (i.e., masked)
from other host servers. This is useful when more than one host server is
attached to the FC I/O blade (e.g., in a SAN). One or more of the LUNs
can be masked from discovery by specific host servers while maintaining
their mapping and accessibility to other host servers via the same port(s).
Host Mapping Vs.
Channel Zoning
5
Channel zoning places an operational restriction on mapped LUNs (for
example, if port 1 is zoned to ports 3 and 4, but LUNs from ports 3
through 6 have been mapped to a specific host server WWPN, the devices
on ports 5 and 6 cannot be accessed from that host via port 1, even though
they are mapped to it; only the devices on ports 3 and 4 would be
accessible from the host via port 1).
Host mapping can be used to control visibility of the media changer
devices (partitions) found on the FC I/O blade internal virtual port, while
channel zoning can be used to create simple access control to the other
target devices. If the host mapping capabilities are used to control
visibility and access for all the LUNs, channel zoning might not be
necessary or desired.
Note:
On the operator panel, the host mapping screens (
Setup > FC
I/O Blades > Host Mapping
) are not available unless FC host
mapping is enabled. See