BladeSystem - General

C7000 / Gen8 blades: the basics for a newbie

Occasional Advisor

C7000 / Gen8 blades: the basics for a newbie

Hi guys,


I’m new to HP Blade systems and in particular Flex-10 fabric.


We currently have a C7000 (commissioned by another team within the organisation using an HP partner for professional services so their understanding of the setup is also limited)


C7000 G2 Enclosure with:

12 empty bays

2x VC Flex 10 Ethernet Modules (455880-B21)

2x VC 8Gb 24-Port FC Modules (466482-B21)


I want to add 2 BL420 Gen8’s to the enclosure but trying to get my head around the setup before approaching our HP partner.


Have verified the enclosure firmware is at a level to support the Gen8 blades, but the Interconnect options between the blades and the enclosure is where I’m getting lost.


As we already have the 10Gb Ethernet Flex-10 modules in the enclosure then I’m assuming all we need to have spec’d on the actual blades is the correct Gen8 options for 10Gb Ethernet and 8Gb FC? And interconnects will be cable-less with connection made via the enclosure midplane?


From reading the HP specifications for the Gen8 blades am I correct that the Ethernet module would take the form of a LOM module, while the 8Gb FC module would be a traditional mezzanine card?




Re: C7000 / Gen8 blades: the basics for a newbie

Ensure that the VC Flex 10 10GB Ethernet modules firmware is at 3.7 or above.


 Port X7 and x8 connect to the internal link between horizontally-adjacent Flex-10 enabled VC-Enet modules. For example if VC Flex-10 modules are installed in interconnect bays 1 and 2, then they are internally linked.  Only modules that are installed horizontally-adjacent are internally linked.  For recommended stacking connections, refer to section of the same name on page 43/242 of the HP Virtual Connect for c-Class BladeSystem User Guide, locatable at the following link:


Flexible LOMs are routed to Interconnect bays 1 and 2 respectively. Though there are Ethernet mezzanine card options, you may choose install Fibre Channel Mezzanine cards in the mezzanine slots and use the VC-FC to route traffic to the fabric. Refer to the above guide for choosing the bay to install the VC-FC modules.


Refer to section Core Options > HP Fibre Channel at the server’s QuickSpecs for information on FC mezzanine options. Furthermore refer to section “Standard Features > HP BladeSystem c-Class Enclosures QuickSpecs: HP BladeSystem c-Class Interconnect and Mezzanine Components at” for mezzanine card options. Following is the link to QuickSpecs to obtain this information:







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Views expressed herein are my personal opinion and are not the views of HPE

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Occasional Advisor

Re: C7000 / Gen8 blades: the basics for a newbie

Thank you Vijayasarathy, most helpful
Honored Contributor

Re: C7000 / Gen8 blades: the basics for a newbie

Is that the complete list of the already-installed I/O modules in the chassis?


Each I/O module at the back of the chassis provides typically one port for each blade, so the I/O modules are shared by all blades in the chassis. So the configuration of the blade must match the I/O modules in the chassis.


The connections between the blade mezzanine slots and I/O modules are hardwired in the backplane and cannot be changed. There are no cables to switch around, and no electronic switching matrix to configure. Attached is a PDF that describes the connections between the blades and the I/O modules in a c7000 chassis: this is probably the "Rosetta stone" you'll need to understand the configuration.


Omissions are possible: if a blade does not need FC connectivity, the mezzanine slot that connects to a FC I/O module can be left empty, and a blade with a specific mezzanine card can be used even if the corresponding I/O module slot(s) are empty.


But if the blade has a configuration that conflicts with the I/O modules (e.g. a FC or SAS mezzanine card would be connecting through a Ethernet-type I/O module), the chassis OA won't allow the blade to power up.


In a c7000 enclosure, the first 2 I/O module slots are always populated by NIC-type I/O modules, since that's where the integrated network  interfaces (LOMs) of the blades are routed by the backplane. So the VC Flex 10 modules are most likely in I/O module slots #1 and #2.


Likewise, the blades always have some integrated network interfaces (LOMs) built in: half-height blades like BL420c Gen8 have 2 of them, while full-height blades have 4.


If you have two FC I/O modules in the chassis, they are most likely in I/O slots #3 and #4, to allow for a FC mezzanine card placed in card slot #1 on each blade.


With the Gen8 blades, the type of the integrated NICs is selectable (=FlexibleLOMs).

 Your chassis has Flex-10 VirtualConnect Ethernet I/O modules. So, you'll want your BL420 Gen8s with one of the 10Gbit FlexibleLOM adapters:

  • 530FLB is a Broadcom 10Gb Ethernet NIC, with a fairly standard set of server NIC features.
  • 554FLB is Emulex-based and provides hardware iSCSI or FCoE functionality in addition to Ethernet. 
  • 560FLB is Intel-based NIC with advanced virtualization support options.

Since your configuration already includes FC I/O modules, maybe you don't care about iSCSI or FCoE? Then the question is, do you prefer a particular NIC manufacturer, or do you need advanced virtualization features?


To use the FC connectivity, you'll need to order a 8 Gb FC mezzanine card and put it in mezzanine slot #1 on your new blades.


You won't need to order any I/O modules, since the existing I/O modules will provide external I/O connectivity.

Occasional Advisor

Re: C7000 / Gen8 blades: the basics for a newbie

Thanks Matti_Kurkela,


The links provided will make good reading.


Yes, the chassis is configured pretty much as you describe.  With interconnect bays 1 & 2 being the VC Flex 10 modules and bays 3 & 4 the 8Gb Fibre Channel VC Modules.


Storage will be our existing FC SAN so yes, no requirement for iSCSI or FCoE.