Hyper-v Error: A device attached to the system is not functioning (0x8007001F)
Posted by Brajesh Panda on June 25, 2012
It happened after we installed backup software & tape autoloader in the parent partition of Windows 2008 r2 hyper-v server. In our case we were using Dell equipment i.e. PowerEdge 510 & PowerValut Autoloader & Symantec 2010 R3 as backup software.
After a little bit digging I found this KB2013544 article.
Cause mentioned in this article as follows;
“There is a timing issue with FSDepends.sys and with VHDMP.sys. This timing issue occurs when certain backup programs are installed on computers that are running Windows Server 2008. By default, the FSDepends.sys start value in the registry is set to Manual. When any third-party backup software loads its tape device driver, the software can sometimes result in FSDepends.sys and VHDMP.sys not initializing correctly.”
Here is little more about FSDepend.sys & VHDMP.sys files.
I changed the registry key as stated in KB article and resolved the issue on next reboot.
Open “HKLM\SYSTEM\CurrentControlSet\Services\FsDepends”; Under the “FsDepends” key, change REG_DWORD value “Start” from “3” to “0”