HDS 2012Sep25 New Hitachi Unified Storage VM (HUS VM)

In Hitachi Unified Storage, Hitachi Vantara, Hitachi VSP, HUS VM, MBPS, SPC, SPC-2 by Administrator1 Comment

HDS recently announced their HUS VM storage system that combines the file storage capabilities of their HUS product family with the enterprise class reliability and functionality of their VSP storage in one new system.


The HUS VM can be purchased in file and block storage, block-only or diskless configurations that follow the previously available and popular USP VM.  Apparently, Hitachi felt that there was a storage market segment that was too small for the VSP and yet had enterprise requirements beyond the HUS family of products.

HUS VM hardware features

The HUS VM is available with two storage controllers that are connected via an Hitachi designed grid switch that combines much of the functionality of the VSP specially designed hardware into one, newly developed ASIC.  The advantage of the grid switch is that cache is inherently shared and data flows through the front-end and back-end ports directly through cache without requiring any additional processor activity during data transfer.  There is one grid switch ASIC in each HUS VM controller.

Each controller is made up of two modules, one with host interfaces, global cache and grid switch on it and the other, with backend interfaces and micro processors with processor memory.  Those two modules for each controller, plus fans, power supplies and a service processor board makes up the HUS VM subsystem for block storage.  HUS VM hardware was specifically designed for easy serviceability and high energy efficiency.

File services are supplied by dual HDS BlueArc SiliconFS file modules.  Two different file module versions are available, similar to the current HUS product family that offers different cluster configurations and performance capabilities.  The file modules connect to the block storage over FC.

The HUS VM supports up to 1152 internal drives but just like the VSP also supports external storage via Hitachi storage virtualization.  HUS VM can have up to 256GB of cache and supports up to 32 or 48 (for diskless systems) 8Gbps FC ports in quad port channel modules.  FCoE and iSCSI are on the road map.  The microprocessors on the HUS VM are latest generation eight-core Intel processors.

HUS VM software

The HUS VM is essentially VSP hardware and runs VSP microcode.  As such, the HUS VM supports enterprise class storage tiering (HDT), thin provisioning (HDP), all the storage replication (HUR and TruCopy®) options and other advanced enterprise functionality available from the VSP today.  The only thing missing in the HUS VM is VSP mainframe (z System) support.  Other than that, it’s almost (~98%) the same VSP code load for HUS VM block controllers.

The new unified Hitachi Command Suite has been modified to support the new HUS VM and all its advanced functionality.  Some file services, such as file or object replication, still require use of the File Module service management but these are being migrated into the Command Suite over time.

Also, the new Command Suite has been updated to ease operational management of the storage, e.g., configuring and using external storage has been greatly simplified.  Further, one can now create HUS VM file systems across block storage all within the Command Suite.

HUS VM storage performance

The HUS VM almost matches sequential performance for an equivalently configured Hitachi VSP storage subsystem.  SPC-2[1] results for an 8-node 512 drive VSP system show a MBPS™ of ~13.1 GB/second.  Not clear if the HUS VM with only dual eight-processor core controllers could quite match that but it should come close.

The big hit is in random I/O or transaction processing. HUS VM random IO performance is about ~1/4th of what the VSP can do but is still pretty respectable.  Of course with this much less hardware something had to give.


Apparently there’s quite a lot of entry level enterprise storage sold today below 100TB.  Hitachi felt there was a need for another gap filling storage system smaller than the VSP but with full enterprise class functionality, reliability and performance.  The integration of high performing file storage to the mix just makes it more appealing to this market segment.

The fact that Hitachi combined all of the VSP’s unique hardware ASICs into one seems a major accomplishment.  Of course to run the rock-solid VSP code on it without extensive modifications they had to do something like this. But now it’s done and they can look forward to taking advantage of this new hardware in future offerings. Stay tuned, as we’re sure there’s more to come on this front, over time.


[This storage announcement dispatch was originally sent out to our newsletter subscribers in September of 2012.  If you would like to receive this information via email please consider signing up for our free monthly newsletter (see subscription request, above right) and we will send our current issue along with download instructions for this and other reports.]

Silverton Consulting, Inc. is a Storage, Strategy & Systems consulting services company, based in the USA offering products and services to the data storage community.


[1] SPC-2 results available from http://www.storageperformance.org/home/


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