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Is that a flash stick in your pocket, VMware, or are you pleased to see us?

Virtual machines are so 2000s - now servers have fat NAND caches to provision

Blocks and Files VMware has, in your correspondent's opinion, punched below its weight in data storage. Undue respect for drive arrays has inhibited its ambitions. This is about to change, though, as the company begins to take responsibility for providing primary storage to applications, and also networking.

Let's consider the basic IT trio of components: compute, storage and networking.

Compute is moving to virtual machines (VMs) operated by a hypervisor (let's say ESXi). In the same way a hypervisor carves up a physical server's processing power into lots of little virtual machines, storage is moving to software-defined virtual storage arrays (VSAs), and networking is moving to software-defined virtual networking (VN): the powerful underlying hardware is chopped into virtual units and provisioned as required depending on demand.

So far, so obvious. In a perfect virtualised world, VMs and VSAs are managed by a hypervisor to run an application or set of applications.

It seems to your humble hack that when VMware was born, it focused on server software and was not interested in being responsible for networked storage.

Now the world is changing over to storage and network software stacks running on hugely powerful commodity server hardware that is about to get even more powerful, as large amounts of flash memory are added to servers and flash takes over the primary data storage role from disk drives (which are slow in flash terms), relegating storage arrays to nearline secondary storage vaults.

I believe this is the data centre landscape that VMware's product strategists are looking at, and they are going to make VMware a power to be reckoned with in the storage area.

Let's consider a few flash facts:

  • Diablo and SMART Storage can provide servers with up to 6.4TB of flash using DIMM-connected modules
  • Micron has a P520 PCIe flash card in development with 16TB of flash on it
  • Fusion-io's ioScale PCIe flash card has up to 3.2TB on it, and a non-volatile NAND chip shrink is coming that should double that

We are looking at servers having tens of terabytes of flash that can be used as an app-accelerating cache; that is, a block storage resource that can be pooled across servers by VSA technology, or as storage memory. It means that a server running on such flash steroids could run many more VMs. Grouped servers become much mote powerful VSA nodes (or virtual network nodes).

Groups of servers with large flash stores linked over fast interconnects, such as InfiniBand, 40GbitE or a PCIe network, can become a reinvigorated SAN with storage pools carved out dynamically for a VM – or several VMs – and moved around as VMs move around, and given defined qualities of services as VMs get compute QoS.

Why should VMware leave the organisation, provisioning and management of storage resources from servers bulked up with such flash steroids to other suppliers whose products and technologies are further away from the applications running in virtualised servers than the hypervisor?

A case can be made for saying that EMC's ViPR should be transferred to VMware; it will run in VMs anyway. A case can be made that VMware should have its own ViPR-like technology, separating control and data planes, for both storage and networking.

I believe that the EMC subsidiary has realised it has the opportunity to play a stronger role in provisioning and managing storage in the powerful servers available today and the vastly more powerful ones coming. It has that opportunity and it should take advantage of it.

After all, the idea that networked storage array suppliers should be responsible for provisioning and managing storage in servers is a nonsense. Those two role should be carried out where that storage is located; in the servers, meaning by the server OS or hypervisor, meaning by the hypervisor because, to be crude, the traditional server OS' are just application wrappers.

The storage centre of gravity is moving closer to servers. They are increasingly virtualised and hypervisors like VMware's ESX will become big beasts in the storage jungle, changing from the puny little weaklings that they resemble now. ®

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