Paul Gregory | 13 June 2013
Windows Server 2012 introduces a new technology that allows any application to be enabled to allow SAN based storage to copy files internally rather than be copied by the Windows Server across the network.
Offload Data Transfer (ODX) supports both the data being copied
between LUNs on a single SAN or between LUNs on different SAN's
(they have to be the same model). The technology will even support
copying of data between 2 Windows Servers which really
improves the performance when performing shared nothing live
migrations with Hyper-V. The benifits of this are lower CPU
utilization, lower Disk I/O lower network utilization but providing
much much faster file copy operations. But as it is enabled by
default how can you know or test if it is working.
Within Windows Server 2012 the following applications support ODX:
- Windows Explorer
- Hyper- V (management operations)
- Copy commands in Windows PowerShell
- Copy commands in a command prompt (including RoboCopy)
The simple way to test ODX is to copy a large file from one LUN
to another with ODX turned off then record CPU, Network Traffic and
Disk I/O in Performance Monitor. Then repeat the same test with ODX
turned on. All the measurements should be significantly less on the
To turn ODX on or off the following registry key need to be changed:
hklm\system\currentcontrolset\control\filesystem\FilterSupportedFeaturesMode A value of 0 ODX is enabled a value of 1 ODX is disabled.
Please watch this video to see the steps needed to test this feature, or attend a training course on Windows Server 2012 @QATraining.