By incorporating software for flexibility and manageability, software-defined storage is redefining the space
BY KTP RADHIKA
From basic business applications to cloud and big data, enterprise technologies have come a long way in the past 10 years. And one of the beneficiaries of these leaps in innovation has been storage. Even a couple of years ago, virtualization was the hottest trend in this space. But not any longer. Redefining storage is what enterprises fondly refer to as SDS, aka software-defined storage. Derived from the software-defined data center (SDDC), SDS is now causing a tectonic shift not just in the storage sector, but also in the IT industry as a whole for its sheer ability to increase efficiency and service velocity in storage.
What does SDS actually do? It pools hardware storage resources and allows them to be programmatically defined, provisioned and managed in the software. This means that automation and pooling of storage through a software control plane gives the ability to provide storage from industry standard servers. This offers CIOs or IT managers a simplified way of storage that is provisioned and managed on industry standard servers at a fraction of the cost. The new design provides the means for storage services to be provisioned and consumed based on policies and can be deployed on a wide range of hardware spanning from vendor-optimized to commodities on cloud.
The whole concept started when VMware and some other players started thinking toward the idea of software defined infrastructure services. That included networking and storage — services that have traditionally been entirely dependent upon specialized hardware systems. Increasing demand for cost effective and flexible storage solutions created the need and is driving the adoption of SDS.
According to research firm Gartner, the Indian IT infrastructure market, comprising server, storage and networking equipment, will total US $2.1 billion (more than Rs. 12,000 crore) in 2013. In this pie, the external controller-based storage is the fastest growing segment with revenues growing from $374.2 million in 2013 to an estimated $702.3 million in 2017.
“Managing storage demands is one of the biggest problems faced by Indian users. So, integrating software driven intelligence in the storage is gaining traction in this market and is expected to solve some of the issues,” notes the Gartner report. According to global research firm Markets and Markets, global SDDC market is estimated at US $396.1 million in 2013 and expects to grow to US $5.41 billion in 2018. Ashish Nadkarni, Research Director at IDC’s Storage Systems, says software-based storage will slowly but surely become a dominant part of every data center, either as a component of a software-defined data center or simply as a way to store data more efficiently and cost-effectively.
Automated and affordable 
SDS is a way for business applications and underlying storage services to share hardware resources. It helps make storage a pooled and freely exchangeable resource across physical boundaries. Traditional external controller based storage systems have made customers feel ‘locked-in’ with specific vendors as most of the storage hardware sold is controlled by the vendor’s proprietary controllers. “In the past few years, we have moved to storage that is driven by software based controllers to eliminate these proprietary controllers. The next gradual progression is towards automating storage provisioning and making storage management smarter yet cost effective,” says Purshottam Purswani, CTO, Atos India.
SDS enables storage resources to be utilized more efficiently. With the help of software, storage administration can be simplified through automated policy-based management without any constraints of underlying physical storage system. Storage control is highly automated and this is better for dynamically serving applications and workloads, especially for the ever-changing applications and workloads in the virtual infrastructure.
Converging applications and storage on the same platform improves utilization rates of compute power and storage with power, cooling, and data center footprint efficiency. Chuck Hollis, Chief Strategist, VMware, states, “SDS offers CIOs a significant simplification to the way storage is provisioned and managed while cutting cost.” According to Barun Lala, Director, Storage, HP India, SDS is inexpensive compared to upfront capital investment for storage hardware. Explaining about HP’s SDS offering —HP Virtual Storage Appliance (VSA), Lala feels that software functionalities in it makes VSA an agile, scalable shared storage solution that can help reduce storage costs by up to 80%. “This affordable solution now features sub-volume tiering automation to optimize performance and cost for dynamic workloads. It is also easy to deploy and manage across enterprise,” he points out.
Making it simpler
SDS looks into the capacity, availability and performance needs and makes application provisioning simpler. Incorporating SDS, enterprises can purchase heterogeneous storage hardware and can prevent hindrances owing to interoperability, inefficient utilization of storage resources and further improve application performance, scalability, minimize application downtime, performs online storage migrations, avoid unnecessary fail-over occurrences and associated application disruption.
Apart from offering these functionalities, software can also manage the storage environment in a dynamic manner and the user can enable or disable functionalities across the enterprise with a fraction of commands. “Today, storage is typically managed in dedicated hardware silos for individual products. This leads to increasingly complex and fragmented management, deployment processes, and skill sets for each silo. With SDS, the opportunity is to provide a unified control plane across these silos, to simplify the provisioning of applications with the best storage system,” Hollis avers. For example, VMware’s SDS tier Virtual SAN (VSAN) implements a policy-based approach to storage management. Users can specify storage attributes — such as capacity, performance and availability — in the form of simple policies associated with individual virtual machines or virtual disks. Storage is instantly provisioned and automatically configured according to the assigned policies.
SDS is not virtualization
SDS usually gets confused with storage virtualization. SDS is more than storage virtualization. It is a logical extension of existing virtualization concepts to new domains and integrating them in ways not previously possible. Tarun Kaura, Director – Technology Sales, India & SAARC, Symantec, agrees. “SDS has the capacity of multiple storage devices or arrays to be amalgamated so that it appears as if it is on a single device. It is not about separating capacity from a storage device, but instead is about separating the storage features or services, from the storage device.” It therefore helps IT professionals use their storage more efficiently without being restricted to a single storage vendor or platform.
Virtualization changed how we think about computing and IT is not the same it used to be. “We are betting that the same thing has begun in the storage world,” explains Hollis. “SDS will simplify storage provisioning and management dramatically for virtual machines. Featuring a scale-out architecture that is fast, resilient and dynamic, it will deliver significantly lower total cost of ownership (TCO) in cases such as virtual desktop infrastructure(VDI), test/development environments and disaster recovery targets,” he adds. With its granular, scale-out approach, it will enable customers to start small and add new servers as performance and capacity needs grow instead of incurring large upfront investments.
Technology wise, SDS, unlike storage virtualization, decouples the control path from the data path. By abstracting the control path, storage management operates at the virtual layer, which gives customers the ability to partition their storage pool into various virtual storage arrays and manage them uniquely by policy. Says Abhijit Potnis, Director, Technology Solutions, EMC India & SAARC, “This is analogous to partitioning a server into a number of virtual machines. This decoupling of the control and data paths enables SDS to centralize all data provisioning and data management tasks, and allows applications to access file and block data as they always have and continue to use the unique data services embedded in the storage arrays.”
Facilitating the cloud
The concept of SDS may be new in the storage industry, but CIO and CTOs who are faced with current priorities to implement or use cloud services can definitely benefit from SDS given that it offers superior integration and customization features, along with the necessary flexibility and scalability that suit cloud services. This will reduce overall storage infrastructure and management costs, transforming the way storage systems are designed and managed. For a cloud vendor, providing tenant-based storage, real time provisioning and scalability is an important factor and SDS allows service providers to manage their storage hardware efficiently. Earlier, management of physical storage was rigid and used to lead to over-provisioning. Now, with SDS storage allocations can be done based on priority and service levels under policy driven storage architecture.
“SDS is not a completely established market. However it is picking up very well,” says Shriranga Mulay, Senior Vice President, IT Engineering, Netmagic Solutions. Netmagic is in the process of implementing SDS and has partnered with Cloudbyte, a storage software vendor, to implement ‘Elastistor’ for their internal requirements and for serving customers. “We will be completing it in the next couple of months and it will help us to keep scaling our storage, according to the requirements. For our cloud customers, SDS will give a choice of choosing the storage they want and get the required performance levels,” he adds.
Purswani of Atos India believes SDS goes a step further to deliver the service from storage pool as per requirement and utilizes best fit provisioning logic which is completely real time, automated and policy driven. “This is more suitable and beneficial when we use most of the applications or services that are cloud based,” he says.
An emerging market
While traditional storage approaches have evolved quickly over the past few years, there are many challenges that outraces the existing solutions. Today, matching the right storage with the right application isn’t the easiest thing to do. Over-provisioning performance, protection and capacity is the norm just to be safe. And there’s plenty of room for increased efficiency on the operational side-making storage an integral part of the virtual administrator’s experience.
Even though the concept of SDS is very new to the industry and understanding the concept is going to take its own course, experts think that it will solve many of those challenges that CIOs faces today. “SDDC is the future of this industry and adoption of SDS is inevitable,” comments Hollis.
According Mulay, SDS will get lot of adoption in online transaction processing (OLTP) applications like e-commerce, portals, etc., and for applications which need a lot of agility. “ It will have a year on year growth of about 40 to 50% in the next few years,” he says.
As of now, global companies have started adopting SDS to satisfy their storage needs. However in India, many of the companies are in the pilot running stage. “Software Defined Storage in India and for overall storage industry is relatively new. We are currently running the software with a few select customers under the Early Adopter Program,” says Potnis of EMC. The players are hopeful of a healthy feedback that can pave the way for robust growth in this high-potential IT vertical.
