Hyper-V 2008 R2 File server BSOD

Hyper-V File Server rebooted with no warning

I'm trying to trace down the cause to be able to prevent this if possible.

BugcheckCode 126 
  BugcheckParameter1 0xffffffffc0000005 
  BugcheckParameter2 0xfffff88004368ff3 
  BugcheckParameter3 0xfffff88001fb8968 
  BugcheckParameter4 0xfffff88001fb81c0 
  SleepInProgress false 
  PowerButtonTimestamp 0