Setting the storage protocol

The storage protocol setting is determined by the protocol that attached the target LUNs to the host.

The following options are available for this setting:

Auto: IBM® Storage Support for Microsoft VSS and VDS automatically selects the appropriate protocol. If no protocol is available on the host, the snapshot fails.

FC: IBM Storage Support for Microsoft VSS and VDS selects the FC protocol. If the FC protocol is not available, the snapshot fails.

iSCSI: IBM Storage Support for Microsoft VSS and VDS selects the iSCSI protocol. If the iSCSI protocol is not available, the snapshot fails.

Issue the following command to set the storage protocol:

ibmvcfg set storageprotocol <auto, fc, iSCSI>

If more than one storage protocol is installed on the host and guest OS, IBM Storage Support for Microsoft VSS and VDS follows an algorithm to selects the correct protocol. The protocol is as follows:

Protocol setting is auto
- If FC and iSCSI coexist, selects FC before iSCSI.
- If iSCSI is installed on both guest and host, selects iSCSI on guest before on host.
Protocol setting is FC
- If FC protocol is available, selects FC protocol on host.
Protocol setting is iSCSI
- Ignore FC configuration with this setting.
- If iSCSI is installed on both guest and host, selects iSCSI on guest before on host.

See Table 1 for the protocol settings and their priorities.

Table 1. Summary table of protocol selections
Protocol Setting	Guest OS	Host	Using
Auto	None	FC, iSCSI	FC on Host
		FC	FC on Host
		iSCSI	iSCSI on host
		None	ERROR
	iSCSI (software initiator)	FC, iSCSI	FC on Host
		FC	FC on Host
		iSCSI	iSCSI on Guest
		None	iSCSI on Guest
FC	None	FC, iSCSI	FC on Host
		FC	FC on Host
		iSCSI	ERROR
		None	ERROR
	iSCSI (software initiator)	FC, iSCSI	FC on Host
		FC	FC on Host
		iSCSI	ERROR
		None	ERROR
iSCSI	None	FC, iSCSI	iSCSI on host
		FC	ERROR
		iSCSI	iSCSI on host
		None	ERROR
	iSCSI (software initiator)	FC, iSCSI	iSCSI on Guest
		FC	ERROR
		iSCSI	iSCSI on Guest
		None	ERROR