Manage storage adapters
A host uses storage adapters to access different types of storage devices. CAS supports SCSI, iSCSI, FC HBA, and FCoE HBA storage adapters.
A host has a default local-SCSI storage adapter and a default open-iSCSI storage adapter. The local-SCSI storage adapter is used to access local disks. The open-iSCSI storage adapter is used to access iSCSI storage. An Open-iSCSI storage adapter has an IQN by default. As a best practice to simplify management and maintenance, edit the IQN.
If a host is configured with hardware FC HBAs or FCoE HBAs (for example, CNA) for accessing FC storage, the storage adapter list also displays detailed information about the FC HBAs or FCoE HBAs.
The system also supports software FCoE adapters. The FCoE protocol stack of the host performs protocol processing for software FCoE adapters, and the NIC performs FCoE forwarding. Software FCoE adapters must work with NICs that support data center bridging and FCoE offload.
If multiple paths exist between a host and SAN storage, traffic can be switched to an available physical link when any element in the SAN network (for example, an adapter, switch, or cable) fails. In addition, the traffic can be balanced over the multiple paths to reduce or even eliminate potential bottlenecks.
By default, the system applies the multipath policies defined by vendors to their respective storage devices. The system provides four multipath policy types, including most recently used, fixed, round robin, and optimal. You can select a multipath policy based on the type of a storage device and enable the multipath policy feature on the storage device.
You can configure multipathing for different storage pools of a host as follows:
iSCSI shared file system—When you add an iSCSI shared file system storage pool, enter multiple service IP addresses for an IP SAN. If you enter only one IP address, multipathing is still enabled by default.
FC shared file system—When you add an FC shared file system storage pool, select multipath for the HBA parameter. For more information, see "Manage storage pools."
iSCSI network storage—Multipathing is disabled by default and is not configurable.
FC network storage—Multipathing is enabled by default and is not configurable.
Operators can scan storage adapters on CVM to discover available LUNs after carving LUNs and configuring LUN mappings on storage servers. To discover the LUNs on iSCSI storage that are assigned to a host, you must add the corresponding storage pools on the host. If CVM cannot discover the LUNs on FC storage for a host, reboot the host.
Prerequisites
Before you configure software FCoE adapters, complete FCoE configuration on switches.
Restrictions and guidelines
Use the following methods to troubleshoot the creation failure of a software FCoE adapter:
Verify that cables are correctly connected.
Click Refresh on the storage adapters page.
Verify that the FCF switch is correctly configured.
Execute the shutdown command and then the undo shutdown command on the interface that connects the FCF switch to the host NIC.
If the rate of the NIC for the created adapter is 10 Gbps, the Rate column displays Unknown for the adapter, and the actual rate is 8Gbps.
You cannot delete a software FCoE adapter if its storage devices have been mounted to storage pools. To delete the adapter, you must first delete the storage pools.
Set the IQN of a storage adapter
On the top navigation bar, click Resources.
From the left navigation pane, select Virtualization.
Click the Expand icon
on the left of CloudOS, and then click the Expand icon 
on the left of a cluster.
Click the name of a host.
Click the Storage Adapters tab.
Click Configure in the Actions column for an open-iSCSI storage adapter.
Enter an IQN, and then click OK.
Scan storage adapters
On the top navigation bar, click Resources.
From the left navigation pane, select Virtualization.
Click the Expand icon
on the left of CloudOS, and then click the Expand icon 
on the left of a cluster.
Click the name of a host.
Click the Storage Adapters tab.
Click Scan in the Actions column for a storage adapter or click Scan All.
Select a scan mode, and then click OK.