All software defined storage (SDS) is definitely not created equal; vendors have released a variety of software to create very different solutions with very different aims. This article will provide a short overview of some popular, established and new software companies.
Nexenta (www.nexenta.com) is at one side of the spectrum with their flagship product NexentaStor, which allows customers to build their own array. NexentaStor will utilise commodity hardware such as 2 servers and disk shelves to provide the storage operating system turning the this underlying commodity hardware into something resembling a typical storage array like a NetApp FAS or an EMC VNX. Nexenta provides reference architectures and does not allow an “anything goes” approach. The main advantage is a generally lower price due to the use of commodity hardware and additional flexibility when it comes to the time of refreshing the hardware – in this scenario it is significantly easier to replace the controllers with the next generation hardware and gain the associated performance benefits for the storage environment. Being software this is not coupled to any specific hardware (within the supported environment). Nexenta is currently working on or has released software for Object Storage, Cloud Connectivity and Orchestration.
PernixData (www.pernixdata.com) is covering a completely different angle of SDS. Their FVP software allows the pooling of server flash (SDS) and RAM to improve the performance of the connected storage for virtualised servers on VMware. Their slogan is to decouple storage performance from capacity. FVP uses a variety of SDSs and/or server RAM on supported platforms (Cisco UCS, Dell PowerEdge, HP DL/BL, IBM x and others) as an additional caching mechanism. A nice feature of FVP is the seamless implementation, i.e. no server or VM reboots are required and no other significant changes in the management of VMs. The implementation can save on capital expenditure for expensive high-performance storage, as with FVP reads and writes are performed locally to fast storage. In addition data protection features are built into FVP to prevent data loss.
A similar approach to PernixData has been taken by Infinio (www.infinio.com), who also aims to improve the performance in VMware virtualised environments. Infinio does not require any additional hardware, but requires the installation of an additional appliance (2 vCPUs, 8GB) on each ESXi server to provide a caching layer to improve storage performance.
More in the expected scope of SDS are the next vendors. AetherStore (https://www.aetherstore.com) was started in 2012 and have just released the first GA version of their software. Pooling all unused capacity on any or all workstations and desktops running the Windows operating system AetherStore creates a secure storage environment at no additional hardware cost – making effective use of unused capacity. Data is distributed multiple times protecting against system failures. AetherStore is targeted at SMB, schools and environments that do not want to invest in separate storage infrastructure.
DateCore (www.datacore.com) call themselves “The Storage Virtualisation Company) and admittedly their SANsymphony-V software has been around for some time. SANsymphony-V virtualises existing storage hardware and can add features like auto-tiering, which in turn can improve performance. Likewise IBM (www.ibm.com) has offered the SAN Volume Controller (SVC) for storage virtualisation since 2003. Both solutions are “in the data path”, i.e. implementation is disruptive as a reboot of servers wanting to use virtualised storage is required.
EMC (www.emc.com) put the emphasis on automation, orchestration and manageability with the ViPR SDS. ViPR lives on the other end of the spectrum to AetherStore (the one with Windows 7 support) and supports EMC arrays as well as a host of 3rd party arrays from Dell, HDS, HP, IBM, NetApp, Oracle and SolidFire (the latter an all-flash array company). ViPRs aim is to reduce the time to provision storage significantly through a self-service portal and automation.
Other companies include Scality (www.scality.com; scalable object store) and StarWind (www.starwindsoftware.com; VirtualSAN for virtualised workloads including Hyper-V). An internet search for “software defined storage” also shows Sanbolic, Maxta, Nutanix, HP, Red Hat, SUSE, Dell, Coraid, Overland Storage, Atlantis USX, StorPool , Compuverde and many more.
Most vendors offer a free trial version. However before trying out any (or all) of these software defined storage solutions, it is important to be clear on
- The goals: What is the SDS supposed to achieve? Cost savings, shorter refresh cycles to make use of the latest technology, longer refresh cycles to enable maximum use of existing hardware, increased flexibility, automation, etc.?
- The implementation requirements: What is necessary to implement the SDS and how disruptive will it be to the existing environment?