Consider the following scenario:
You use Storage Spaces to create storage pools on a Windows Server 2012 or Windows Server 2012 R2-based failover cluster.
You have a file server or scale-out file server resource that hosts continuously available Server Message Block (SMB) 3.0 (or a later version) shares that are backed by the storage pools.
You try to copy large files from a Windows 8 or Windows Server 2012 computer to the continuously available SMB shares.
In this scenario, the observed copy throughput is significantly lower than what the connected network and storage system can support.
To resolve this issue, install update 2934016. For more information about how to obtain update 2934016, click the following article number to view the article in the Microsoft Knowledge Base:
2934016 Windows RT, Windows 8, and Windows Server 2012 update rollup: April 2014
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates