vSphere 5.1 Storage Enhancements – Part 5: Storage Protocols

There are a number of storage protocol enhancements in vSphere 5.1.

Boot from Software FCoE

vSphere 5.0 introduced a new software Fibre Channel over Ethernet (FCoE) adapter. A software FCoE adapter is software code that performs some of the FCoE processing & can be used with a number of NICs that support partial FCoE offload. The software adapter needs to be activated by the vSphere administrator before it can be used, similar to Software iSCSI.

In vSphere 5.1, Boot from Software FCoE enables an ESXi host to boot from a FCoE LUN using a Network Interface Card with FCoE boot capabilities and VMware’s Software FCoE driver. A number of configuration details needs to be added to the NIC, such as VLAN ID, LUN ID, WWPN of target, etc. The screen shot below shows LUN ID 50 from an EMC VNX successfully discovered during the boot process:

16Gb HBA Support

VMware introduced support for 16Gb Fibe Channel HBA with vSphere 5.0. However the 16Gb HBA had to be throttled to work at 8Gb for supportability reasons. vSphere 5.1 introduces support for 16Gb FC HBAs running at 16Gb.

Note however that there is no 16Gb end-to-end support for FC in vSphere 5.1, so to get full bandwidth, you will need to zone to multiple 8Gb FC array ports as shown below:

iSCSI jumbo frames

10Gb iSCSI SANs often depend on having larger MTU (Maximum Transmission Unit) sizes to take full advantage of the available throughput of the network. VMware has added jumbo frame support for all iSCSI adapters in vSphere 5.1, complete with UI support.  This enhancement has been added to Software iSCSI Adapters, Independent Hardware iSCSI adapters  & Dependent Hardware iSCSI adapters .

Independent Hardware iSCSI adapters maintain their own networking and target configuration, and also provide a ‘3rd party’ driver, e.g. Qlogic qla4xxx iSCSI driver. Dependent hardware iSCSI adapters depend on VMkernel networking configuration as well as VMware Software iSCSI implementation for session management, e.g. Broadcom’s bnx2i iSCSI driver.

For software iSCSI adapters, the administrator must make sure that the vSwitch and the Network Interface Card backing the adapters are configured to support the larger MTUs to avoid problems with mismatched MTUs.

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