Assigning Luns To Storage Subsystems; Read-Only Zoning; Guidelines To Configure Read-Only Zones - Cisco DS-C9216I-K9 Configuration Manual

Chapter 15 Configuring and Managing Zones
When LUN 0 is not included within a zone, then, as per standards requirements, control traffic to LUN
0 (for example, REPORT_LUNS, INQUIRY) is supported, but data traffic to LUN 0 (for example,
READ, WRITE) is denied.
Caution LUN zoning can only be implemented in Cisco MDS 9000 Family switches. If LUN zoning is
implemented in a switch, you cannot configure interop mode in that switch.

Assigning LUNs to Storage Subsystems

LUN masking and mapping restricts server access to specific LUNs. If LUN masking is enabled on a
storage subsystem and if you want to perform additional LUN zoning in a Cisco MDS 9000 Family
switch, obtain the LUN number for each Host Bus Adapter (HBA) from the storage subsystem and then
configure the LUN-based zone procedure provided in the preceding section.
Refer to the relevant user manuals to obtain the LUN number for each HBA.
If you make any errors when configuring this scenario, you are prone to lose data.
Caution

Read-Only Zoning

Read-only zoning can be implemented in Cisco MDS 9000 Family switches running Cisco MDS
SAN-OS Release 1.2(x) or above.
By default, an initiator has both read and write access to the target's media when they are members of
the same Fibre Channel zone. The read-only zone feature allows members to have only read access to
the media within a read-only Fibre Channel zone.
You can also configure LUN zones as read-only zones.

Guidelines to Configure Read-Only Zones

Any zone can be identified as a read-only zone. By default all zones have read-write permission unless
explicitly configured as a read-only zone.
Follow these guidelines when configuring read-only zones:
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The read-only zone feature behaves as designed if FAT16 or FAT32 file system is used with the
above-mentioned Windows operating systems.
OL-7753-01
If read-only zones are implemented, the switch prevents write access to user data within the zone.
If two members belong to a read-only zone and to a read-write zone, read-only zone has priority and
write access is denied.
LUN zoning can only be implemented in Cisco MDS 9000 Family switches. If LUN zoning is
implemented in a switch, you cannot configure interop mode in that switch.
Read-only volumes are not supported by some operating system and file system combinations (for
example, Windows NT or Windows 2000 and NTFS file system). Volumes within read-only zones
are not available to such hosts. However, if these hosts are already booted when the read-only zones
are activated, then read-only volumes are available to those hosts.
Cisco MDS 9000 Fabric Manager Switch Configuration Guide
Read-Only Zoning
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