Client machine running win 2008-r2 64 bit under hyper-v. Tsm client 6.4.2. Several errors all related to vss. Extract from dsmerror.log follows.
09/09/2015 06:30:20 ANS5250E An unexpected error was encountered. TSM function name : AddToSnapshotSet TSM function : 'AddToSnapshotSet failed with error VSS_E_UNEXPECTED_PROVIDER_ERROR. 0X8004230F' TSM return code : -2147212529 TSM file : ..\..\common\winnt\asrutil.cpp (2281) 09/09/2015 06:30:20 ANS5250E An unexpected error was encountered. TSM function name : AddToSnapshotSet TSM function : 'AddToSnapshotSet failed with error VSS_E_UNEXPECTED_PROVIDER_ERROR. 0X8004230F' TSM return code : -2147212529 TSM file : ..\..\common\winnt\asrutil.cpp (2281) 09/09/2015 06:30:21 ANS5250E An unexpected error was encountered. TSM function name : BackupComplete() TSM function : 'BackupComplete() failed with error VSS_E_BAD_STATE. 0X80042301' TSM return code : -2147212543 TSM file : ..\..\common\winnt\asrutil.cpp (2493) 09/09/2015 06:30:21 ANS1468E Backing up Automated System Recovery (ASR) files failed. No files will be backed up. 09/09/2015 06:30:22 ANS1327W The snapshot operation for 'C:' failed with error code: -1. 09/09/2015 06:30:22 ANS5250E An unexpected error was encountered. TSM function name : BaStartSnapshot TSM function : initializeSnapshotSet() failed, check Microsoft Application event log for VSS errors TSM return code : -1 TSM file : ..\..\common\ba\backsnap.cpp (6368) 09/09/2015 06:30:22 ANS5258E Microsoft volume shadow copy snapshot initialization failed. 09/09/2015 06:30:22 ANS5283E The operation was unsuccessful. 09/09/2015 06:30:22 ANS1377W The client was unable to obtain a snapshot of '\\libmysql\c$'. The operation will continue without snapshot support. Not sure where to go from here. Many articles on the web about win 2003, haven't found much for this.