Hu Yoshida

Software (re)Defined Storage

Blog Post created by Hu Yoshida Employee on Jun 23, 2015

With Hitachi Storage Virtualization you can redefine your already installed storage assets as the latest Hitachi VSP G Series array through software. This software is the Storage Virtualization Operating System (SVOS), which runs in all the VSP Family storage systems from the smallest 2U midrange G200 to the largest enterprise G1000. By simply connecting the fibre channel ports of your existing storage system to the front-end ports of any Hitachi VSP system, SVOS can discover your existing LUNs and enable them with all the latest functionality of Hitachi storage systems.


Why would you want to do this?


Extend the life of your existing storage to defray increasing capacity costs

This may be news to some people, but the cost of storage capacity is no longer eroding at 30-32 % per year. IDC’s Worldwide Hard Disk Drive Forecast for 2015 to 2019, published in May 2015, predicts that “Slow HDD areal density (capacity per disk) growth means that a steadily increasing number of components per drive will be needed on average to reach higher capacity points, particularly for the enterprise segment. This dynamic will push the overall blended average HDD ASP (Average Selling Price) higher each year over the forecast period….”

The new 6 TB capacity disk drives have additional disks and heads in them, which brings additional cost. The economics of a 32% annual price erosion meant that we would depreciate our storage systems every 3 to 5 years since it was cheaper to buy the denser new capacity than maintain the old.  Now that the price erosion has slowed down and started to reverse, we should consider extending the life of storage capacity and amortize it over 5 to 7 or even 10 years. However, the pace of new storage functionality is increasing every year, so we need to keep current with the software functionality in the storage controller. Therefore we need to separate the storage capacity from the storage controller and treat them differently in the tech refresh cycle. Since Hitachi provides virtualization with SVOS we are able to extend the life of existing storage by connecting them to our VSP Family controllers without the need to buy whole new storage systems. Other storage virtualization solutions like EMC ViPR and IBM SVC are simple virtualization proxies or pass through, and cannot provide new storage system’s capabilities. I would expect an increasing use of Hitachi SVOS virtualization to extend the life cycle of storage systems to compensate for the rising price of disk storage capacity


Enable your storage with the latest high availability features.

The hot new availability feature is Global Active Device, which enables a virtual volume to be written and read on two physically separate G Series systems. If one system should be unavailable for any reason, applications continue to run on the other controller without any need for down time, thus delivering zero RTO (Recovery Time Objective) and zero RPO (Recovery Point objective). Other availability features include, 1024 virtual snapshots (Hitachi Thin Image) for more granular point in time recovery and journal based asynchronous replication for faster recovery in the case of replication disruptions. If your storage is virtualized through the G400 to G1000 systems they could also participate in the industry’s only 100% data availability guarantee. (The G200 supports the same virtualization functionality, but does not – today – offer a 100% data availability guarantee.)


Non-Disruptive Migration

Without storage virtualization, the migration of storage from one storage system to another can be very disruptive. Since migration must be done without disrupting applications, migrations occur during weekends when the applications can tolerate some down time. As the amount of data and applications increase, the demand for the number of weekend windows for migration increases and it may take months or even a year before the migration can be completed. In the meantime you have two systems on the floor consuming power, cooling and floor space, and the new system is one year into its depreciation cycle before you have full use of it. With SVOS, there will be a short disruption while your existing system is connected to the G series, but from then on you have immediate access to all the functionality of the new G series on your existing LUNs. If you want to get rid of the old storage, the migration of the data from the old box can be done automatically in the background, so while the movement of data is not immediate, it will take a lot less time than moving a number of TBs every weekend. There will also be less chance for human error. Once you connect to the G series, from then on you will enjoy non-disruptive migration for future tech refreshes as long as the new controllers are Hitachi controllers.


Flash Acceleration

SVOS understands the difference in Flash technology over disk technology and has optimized the code path in the controller for SSDs and Hitachi Accelerated Flash modules so that flash storage systems may see higher performance when virtualized behind the G series. SVOS can move data from the external flash drives into an internal flash tier in the G series, where it may see higher performance and SVOS can add new capabilities to existing All Flash Array (AFA) storage systems. One data center director told me that he bought an AFA, and found a year later that he had bought an All Flash JBOD (Just a Bunch of Disks). The application was still enjoying flash performance, but most of the data on the AFA was not active. He wished that he could automatically tier the inactive data onto lower cost tiers of storage and reallocate the inactive flash capacity to other applications. He also wanted to do replication of the data for disaster recovery through the controller rather than through the software in the processors. Attaching the AFA behind our SVOS would enable him to get all the enterprise functionality he needed including dynamic tiering and replication.


Redefining block to file storage.

The VSP family is comprised of unified storage systems, meaning that they can support file as well as block. Today that is through an advanced Hitachi NAS gateway with integrated management.  In the future, the Hitachi NAS technology will also be available in even more integrated form factors, while maintaining the unique architecture that delivers such high performance.  If you want to convert your block storage to file storage, the SVOS software can do this as well. If you want to refresh your installed filer we can non-disruptively migrate your old filer by connecting to the network, taking over the IP address and migrating the old data from your old filer in the background while the new data is written to the VSP family over the IP network. The G series file is our HNAS, high performance NAS system with primary file deduplication.


Support for APIs

The industry is moving more to open APIs, client providers, and adapters to extend software defined storage to software defined data center. Once your storage system is connected to the VSP G Series, SVOS will enable your storage with access to our latest support for APIs, like VASA and VVOLs for VMware, storage adapters for Oracle Enterprise, RMAN, and VM, and Cinder providers for Open Stack as well as many others. Your existing storage can access these API’s once they are virtualized by SVOS.


Simplified Management and lower software costs

Once your external storage is configured for LUNs, and is connected to SVOS through the VSP everything is managed through our one set of management tools. No need to have separate management tools for enterprise and midrange systems. No need to have separate replication licenses for midrange or enterprise systems or different vendor storage as long as they are virtualized by SVOS.



SVOS is software that not only defines the capabilities of our VSP G series of storage systems from midrange to enterprise; it can also redefine your existing storage providing:

  • Reduced cost by extending the economic life of storage
  • Higher availability with Global Active Device       
  • Eliminate the disruption and cost of tech refresh
  • Accelerate and enhance the capability of flash
  • Unification and enhancement of file storage
  • APIs for software defined data center
  • One pane of glass management for reduced licensing costs and simplification