White Papers

Configure server objects on SC Series storage
19 Dell EMC SC Series Storage and Microsoft Multipath I/O | CML1004
4.4 Restrict volume mapping paths
On an SC Series array that is configured to use both FC and iSCSI, it is possible to configure hosts to use
FC, iSCSI, or both transports concurrently when mapping a SAN volume. While this is not a common
configuration, there are valid use cases, such as when an environment migrates from one type of transport to
another, and for a time, both transports are needed. If the SC Series array and a host support both FC and
iSCSI when mapping a new volume, all available FC and iSCSI paths are mapped for that volume unless the
advanced mapping button is used to restrict mapping paths to FC only, iSCSI only, or a specific FC HBA port
or iSCSI port. To restrict mapping paths when mapping a volume to a server:
1. Log in to the Dell Storage Manager client.
2. Under the Storage tab, expand Volumes and locate desired volume.
3. Right-click the volume and select Map Volume to Server. The Map Volume to Server window
appears.
4. Select a server and click Next.
5. Click Advanced Options.
6. Under Restrict Mapping Paths, uncheck the box to Map to All Available Ports.
7. Select one of the following:
- Map using specific server ports (check the specific server ports desired)
- Limit ports by transport type (select the desired transport from the drop-down menu)
Note: The option to limit ports by transport type is only available on SC Series arrays that have more than
one transport type available (Fibre Channel and iSCSI).
Note: Using mixed transports concurrently on the same Windows server volume is not supported with
Windows Server 2012 R2 and newer. With Windows Server 2012 R2 and newer, when a LUN is presented to
the host that is using both Fibre Channel and iSCSI, the host will default to one transport (typically Fibre
Channel is chosen as the preferred transport by the host) and ignore the other transport. If all paths for the
preferred transport go down, the host may not send data using the alternate transport without a disk re-scan,
and this may cause a service interruption. This is default Windows Server behavior. For servers configured to
use both FC and iSCSI, mapping one data volume with FC ports only, and another data volume with iSCSI
ports only, is supported as long as each volume is configured to use only a single transport.
To view the list of mapped paths for a volume that are already mapped to a server, expand the Volumes tree,
select the desired volume, click the Mappings tab, and view the information under Mapping Details.