Had an issue on some new Server 2012 Hyper-V clustered hosts. Started seeing the following error in the logs:
Cluster Shared Volume 'SERVERNAME' ('') has identified one or more active filter drivers on this device stack that could interfere with CSV operations. I/O access will be redirected to the storage device over the network through another Cluster node. This may result in degraded performance. Please contact the filter driver vendor to verify interoperability with Cluster Shared Volumes.
Active filter drivers found:
???????????????????????
Yes, those are random characters in the error message, so it’s difficult to track down the filter driver in question.
This seems to match the same issue in Server 2008 R2 – Redirected mode is enabled unexpectedly in a Cluster Shared Volume when you are running a third-party application in a Windows Server 2008 R2-based cluster
In the Microsoft KB notes, they state one of the conditions as being:
- The third-party application has a mini-filter driver that uses an altitude value to determine the load order of the mini-filter driver.
- The altitude value contains a decimal point.
Running fltmc.exe on these hosts shows the following filter drivers loaded:
The filter driver with the decimal point is stcvsm, the “StorageCraft Volume Snapshot Driver” The problem has only been occurring recently, after I installed ShadowProtect.
I’ve had to uninstall ShadowProtect from these servers until it’s officially supported on Server 2012. According to StorageCraft, that should be 90 days after the official launch date of Server 2012. That means there should be a new version of ShadowProtect around the 3rd of December 2012.
User Error 
I have installed the Server 2012 supported version 5.0 and it’s new update 5.01 and I still have this issue. I cannot move my storage to a node with Shadow Protect installed and receive the redirected access error.
If I uninstall shadow protect the node and csv work as expected.
I have contacted Strorage Craft support for assistance.
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Thanks for the update Stephen. Good to know.
I haven’t yet had a chance to install 5.x on any of my servers.
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I’ve been experiencing the exact same issue with CSVs in 2012 after installing CA ArcServe Backup R16.5, which was supposed to support Server 2012. However, I’ve ran into an issue where the ofadriver (open-file agent driver) causes my CSVs to go into a Redirected Access mode if the CSV owner has this driver installed.
Sure enough after I remove the newly installed program the CSVs work as expected.
Other than the Redirected Access issues I did not notice any pain elsewhere. The VMs all functioned and the nodes were all okay… although I’m rather sure that in a case where failure occurred the CSVs would not fail over to the nodes with the bad driver installed.
Cluster Logs:
Cluster Shared Volume ‘Volume6’ (”) has identified one or more active filter drivers on this device stack that could interfere with CSV operations. I/O access will be redirected to the storage device over the network through another Cluster node. This may result in degraded performance. Please contact the filter driver vendor to verify interoperability with Cluster Shared Volumes.
Active filter drivers found:
??????????????????????????
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Thanks DAN, i have the same problem with the CA open files agent on Windows Server 2012 R2 and CA V17… so i guess that the problem is still present.
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