I recently came across a customer that had limited space, power and cooling in there datacentre (very few who don’t right?) but wanted to put in a Vblock but to do so would need to split most of the UCS chassis across multiple racks and at opposing ends of the datahall. Traditionally, when I design and spec a UCS system I use the default ‘passive‘ Copper Twinax SFP+. In the event I need to provide cabling for Fabric Interconnects that are more that 5 meters away from the chassis then I would use ‘active‘ Copper Twinax SFP+ as these can go up to 10 meters.
But in this case the distances are over 30 meters. The alternative is go optical by using SFP+ modules (SFP-H10GB-SR) which can more than compensate for almost any datacentre distances (300m or so).
A few of you may have noticed I said this was a Vblock, you may be thinking you will not be aloud to do this with a Vblock as it brakes the default spec. While it does go against what’s in the design for a Vblock, it is a great example of how the Vblock products are actually flexible and not as rigid a people may think and exceptions can be raised when genuine requirements demand it.
Click here for more info on installing and configuring a UCS chassis and cabling it up.
Thanks to a Andrew Sharrock (@AndrewSharrock) for pointing this one out. As of UCS Software release 1.4 Fabric Extender Transceivers have been supported and are an alternative to using the above. You can get up to 100m from a FET and it supports OM2, 3 and 4 cables. I have a feeling not many people have deployed this as its Google doesn’t bring many results back on this subject but its an option. I’m not sure if VCE support it within a Vblock either (VCE peeps are welcome to confirm or deny this in the comments).
To replace a copper Twinax SFP+ transceiver with an optical SFP+ transceiver, follow these steps:
Step 1 Remove the copper Twinax SFP+ from the I/O module port by pulling gently on the rubber loop (see Figure 2-19). The cable and SFP+ transceiver come out as a single unit, leaving the I/O module port empty.
Step 2 Insert the optical SFP+ transceiver into the I/O module port. Make sure that it clicks firmly into place.
Step 3 Plug the fiber optic cable into the optical SFP+ transceiver (see Figure 2-20).
Figure 2-19 Removing a Twinax Copper SFP+ Transceiver
Figure 2-20 Replacing a Copper SFP+ Transceiver With an Optical SFP+ Transceiver