HP Virtual Connect for c-Class BladeSystem Version 3.30 User Guide

Virtual Connect fabrics 105
Virtual Connect fabrics
Understanding FC fabrics and bay groups
The VC-FC modules enable the c-Class administrator to reduce FC cabling by using N_Port_ID virtualization
(NPIV). The HP VC-FC and FlexFabric modules act as an HBA aggregator where each NPIV-enabled N-port
uplink can carry the FC traffic for multiple HBAs.
Because VC-FC modules use an N-port uplink, they can be connected to data center Brocade, McData,
Cisco, and Qlogic FC switches that support the NPIV protocol. When the server blade HBAs log in to the
fabric through the VC-FC module, the HBA WWN is visible to the FC switch name server and can be
managed as if it was connected directly.
IMPORTANT: The VC-FC modules and FlexFabric FC ports must be connected to a data center
Fibre Channel switch that supports NPIV. Most switches support NPIV by default and no
configuration is necessary. See the switch firmware documentation for information to determine
whether a specific switch supports NPIV and for instructions on enabling this support.
The VC-FC module has either four or eight uplinks. Each uplink is independent of the other uplinks and can
use NPIV to aggregate up to 16 physical server HBA N-port links into a single N-port uplink.
You can group multiple VC-FC module uplinks logically into a Virtual Connect fabric when the uplinks are
attached to the same Fibre Channel SAN fabric. You can also create multiple Virtual Connect fabrics on the
same VC-FC module, and each of these fabrics can connect to a different physical SAN. You can connect to
up to four SAN fabrics from one 4-port VC-FC module or FlexFabric module, and up to eight SAN fabrics
from one 8-port VC-FC module.
If NPIV capability of a SAN fabric switch port is lost, the disabled uplink port of the VC-FC module remains
disabled until the module is reset. HP requires connectivity to NPIV-enabled switches for all VC-FC modules
and FlexFabric FC ports.
In a multi-enclosure environment, all enclosures must have the same VC-FC and FlexFabric module
configuration. For example, if the local enclosure has VC-FC modules in bays 3 and 4, each remote
enclosure must also have VC-FC modules in bays 3 and 4. This is called an FC bay group. For more
information, see the HP Virtual Connect for c-Class BladeSystem Setup and Installation Guide on the Installing
tab of the HP BladeSystem Technical Resources website
(http://www.hp.com/go/bladesystem/documentation).
Virtual Connect fabric
By default, all of the VC-FC module uplinks are grouped into a single fabric, distributing connectivity from all
16 server blades in the enclosure. If any uplink port becomes disabled or is no longer connected to the SAN,
server HBA ports logged in through that port are automatically reconnected to the fabric through one of the
remaining uplink ports. However, when a previously failed uplink is reconnected to the fabric, no server HBA
logins are moved to the newly available port. This can cause an unbalanced situation, where some uplink
ports have more server HBA logins than others. VCM enables you to manually redistribute server logins at
any time using the GUI or the CLI.