Comment Great beasts can be killed by a 1,000 cuts, bleeding to death from the myriad slashes in their bodies – none of which, on their own, is a killer. And this, it seems, is the way things are going for big-brand storage arrays, as upstarts slice away at the market with converged systems, virtual SANs, all-flash kit, hybrid devices, object storage, software-defined storage and the cloud.
Up until a few years ago, say around 2009, storage arrays ruled supreme, with monolithic, multi-controller arrays on the top of the heap: VMAX, VSP, DS8000, and dual-controller arrays beneath them – NetApp FAS, EMC VNX, HP 3PAR, and Dell Compellent for example. There were rumblings in the storage jungle from object storage, early flash arrays like those from Violin Memory, and scale-out filers like Isilon, but the rumbles did not take centre stage.
These were early signs that the classic storage array was under attack because it was becoming too limiting, complex and expensive for more and more use-cases.
Another indication was the rise of virtual SANs, software-only SANs like the one produced by LeftHand Networks, with LeftHand acquired by HP and the P4000 product emerging. Shared storage went through a renaissance, as had occurred with the previous emergence of Compellent, EqualLogic, 3PAR, XIV and others – all acquired and absorbed into the mainstream suppliers' product lines.
But soon developers and engineers realised that there really were other ways of providing shared storage that sorted out monolithic and dual-controller array issues and helped bring compute and storage closer together:
- Object storage – things like erasure codes and dispersal algorithms solved the issue of lengthy RAID rebuilds and dual and triple disk failures in standard arrays, as well as bypassing the limitations of file systems when looking after billions of files.
- All-flash arrays – enabled storage to keep up with multi-socket, multi-core CPUS running virtual machines, but at a cost. Suppliers include Pure Storage, TMS (bought by IBM), Solidfire, and Whiptail (bought by Cisco).
- Hybrid flash/disk drive arrays – with new controller software, from suppliers such as Nimble Storage, Tegile and Tintri, provided 90 per cent of an all-flash array's performance combined with disk drive array capacity levels and better performance and management from the new software. Plus their prices were – are – substantially below standard storage arrays.
- Server flash storage – pioneered by Fusion-io, it provided even faster access to high access rate, high-value data.
- Software-only SANs and filers – this kit, from suppliers such as DataCore, Nexenta and Sanbolic, enabled the channel to build shared storage using commodity components and sell systems at substantially lower price points than mainstream suppliers.
- Virtual SANs – these built on the LeftHand concept by aggregating a clustered server's directly attached storage into a single shared storage pool.
- Converged systems – took on this idea and added it to hardware combining servers and storage to provide simplified scale-out systems. Suppliers include Nutanix, Simplivity, Scale Computing, Maxta and others.
- Software-defined storage – It's a vague term, and often includes the idea of abstracting shared storage and virtualising the hardware even more. This means that the software, whatever its original design point, can provide a shared resource pool for different kinds of access – HDFS, object, file or block – with these being dynamically changeable to respond to storage access needs by different applications. VSANs are generally involved too.
- The cloud – replaces on-premises storage arrays with storage in the cloud service provider's remote data centres, often built in a customised way from off-the-shelf components with specially written software to cope with the extraordinary scale involved. The three main players here are Amazon, Google and Microsoft with Azure. The cost of using cloud storage is an operating expense rather than a capital expense and is claimed to be much lower, in total cost of ownership terms, than owning and operating on-premises arrays.