In a recent technical brief HP zooms in on the new HP P6000 Enterprise Virtual Array combined with
Hyper-V. The paper discusses a number of topics related to HP’s new storage array:

  • Thin Provisioning
  • LUN Migration
  • FC, iSCSI and FCoE
  • Performance

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Thin Provisioning

When using HP’s Thin Provisioning with Hyper-V it is important to choose the correct type:

Fixed VHD
With a fixed VHD, the VHD file consumes the specified capacity at creation time, thereby allocating the initially requested drive space all at once and limiting fragmentation of the VHD file on disk. From the VM’s perspective, this VHD type then behaves much like any disk presented to an OS. The VHD file represents a hard drive. As data is written to a hard drive, the data fills that drive; or in this case, the VM writes data in the existing VHD file, but does not expand that file, therefore it should not be used with P6000 Thin Provisioned Vdisks.
Dynamically expanding VHD
With a dynamically expanding VHD, a maximum capacity is specified. However, much like HP P6000 EVA thin provisioned volumes upon creation, the VHD file only grows to consume as much capacity on the volume as is currently required. As the VM writes more data to the VHD, the file dynamically grows until it reaches the maximum capacity specified at creation time. Because dynamically expanding VHDs only consume the capacity they currently need, they are very efficient for disk capacity savings. By nature VHDs are good candidates for Vdisks that use HP P6000 EVA Thin Provisioning.

LUN Migration

Secondly LUN/RAID migration can now be performed online which means no downtime for the Hyper-V environment. It is easier to assign data to the right storage tier, even after the storage array has been designed, installed and configured.

FC, iSCSI and FCoE

HP EVA has primarily been a Fibre Channel storage array. Now both iSCSI  (1GbE & 10GbE) and FCoE are available options. It was already possible to connect Hyper-V hosts to FC SANs but with the current versions of Hyper-V only iSCSI or FC via NPIV supported HBA’s was possible for guests.

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Performance

HP tests have shown that fixed VHDs achieve up to 7% more IOPS and at a 7 percent lower latency compared to dynamically expanding VHDs.

Having worked with EVA since 2001 and Hyper-V since 2007, I second the conclusion that “with the HP P6000 EVA family, HP BladeSystem components and Hyper-V, businesses can create a highly available and high-performance solution.”

The full technical brief can be found at:
http://h20195.www2.hp.com/V2/getdocument.aspx?docname=4AA2-5604ENW.pdf