In the article on composable disaggregated infrastructure (CDI), we touched on the adoption of the non-volatile memory express (NVMe™) interface for direct connection of flash storage to physical servers, but the real advance that enables CDI is the adoption of NVMe over Fabrics (NVMe-oF™), and specifically over an Ethernet or IP fabric.
To understand what the problem is, we need to back up a few years. Until SSDs gained popularity, disks were directly connected via SAS or SATA connections, and things were good. Because operating systems and applications needed to wait for disks – both rotational delays and head seek times were significant – SAS and SATA standards took those delays into account, enabling heads and tracks to be in the right place for reads or writes to occur. However, when SSDs came along, those delays were eliminated in a flash (pun intended), rendering SAS and SATA as obstacles to SSD performance.
Thus, the NVMe standard came to be in 2011, bringing SSD connectivity to the popular PCI Express (PCIe) bus used for all manner of server expansion. For nearly a decade NVMe has absolutely accelerated SSD adoption across the enterprise, with one little problem. Although it’s fantastic for direct attached storage, most systems are not designed to take advantage of NVMe capabilities, which made sharing SSDs beyond their attached servers quite inefficient.
So, how do you address the needs of CDI, where sharing storage resources is critical to gaining the flexibility and agility that composability demands? One answer is adding Ethernet fabric support for NVMe, and that’s exactly what NVMe-oF delivers.
Ethernet is everywhere. It has the performance needed to support SSD sharing today, and a roadmap that quadruples performance in the near future. Ethernet and IP networking go hand in hand, and an Ethernet fabric not only makes technical sense, it is the logical choice since it is ubiquitous and is where R&D investments continue to be made worldwide. It is not that other fabrics such as Infiniband or Fibre Channel don’t have a value, it’s simply that Ethernet is where the most investment is today and for the foreseeable future, while offering an outstanding cost advantage.
The end result is a fabric that simplifies composable infrastructure by being the default backbone of nearly every enterprise network. Western Digital’s OpenFlex™ composable infrastructure combines the best in SSD technology, NVMe-oF, and an open API to deliver the kind of scalability to every enterprise that many hyperscalers and telcos already have in their data centers – without the need for forklift upgrades every time new applications roll out. In the purest sense, NVMe-oF SSDs are storage devices that connect with Ethernet instead of SATA or SAS, enabling CDI, increasing agility, and powering the modernization of enterprise IT infrastructure.
Click here to learn more about how Western Digital’s CDI initiatives can help accelerate your agility.