The recent announcement by Cisco of 32Gbps capability in its MDS 9700 Director switch and UCS C-series server products means the two major storage networking hardware makers are now able to offer the next generation of Fibre Channel bandwidth to customers; Brocade already did last summer with its Gen 6 products.
With 768 ports and a maximum bandwidth of around 1.5Tbps, Cisco has targeted potential MDS 9700 customers as those with high bandwidth requirements, such as in virtualised environments, those using flash arrays, and to support NVMe flash storage.
For now they’re unlikely to make a lot of difference to those using NVMe arrays because simply replacing SAS and SATA drives in the array with NVMe drives means there’s still a bottleneck at the storage array controller.
But, Cisco and Brocade now also offer NVMe-over-Fibre Channel fabric connectivity. There aren’t any storage array products that can fully take advantage of NVMf-FC yet, but when they do the potential of flash storage will be hugely boosted.
That’s because NVMe – a PCIe-based protocol – offers huge performance gains for flash storage over existing SAS and SATA connection protocols.
For now mostly, however, NVMe-connected flash drives only realise their full potential in what are effectively direct-attached storage deployments.
Even with NVMf – which allows NVMe to be transported over Ethernet or Fibre Channel – NVMe can’t gain its full potential as back end storage and across a fabric/network as shared storage as we know it.
That’s because the gains brought by NVMe are nullified to a large extent by the storage array controller that provides protocol handling, storage addressing and provisioning, RAID, features such as data protection, data reduction etc.
That is, until storage controllers have sufficient processing power to not be a bottleneck.
But for now at least NVMe-capable drives exist, a transport (NVMf) exists and the two major storage networking suppliers support it. All we’re waiting for are the array vendors.