I'd been using Registry Backup on a system running XP pro for at least a year without any problems. Recently, however,
it started throwing error dialogs saying the backup had errors. This happens the vast majority of the time now, but
occasionally, it is able to complete the backup normally.
I noticed that, while the backup was being attempted, it showed NO for Volume Shadow Copy Running and NO for
Volume Shadow Copy Ready, so it eventually defaulted to Fallback Method and was unable to fully complete the
backup, thus the error dialog. Sometimes Volume Shadow Copy Running flashes YES for a second or so and then
goes back to NO, but not always. On the one or two occasions that it was able to complete the backup while I was
monitoring it, it showed YES for both Running and Ready the entire time. It seems to be entirely random whether VSS
works or doesn't work.
I also used Task Manager to observe which processes were running while I attempted backups. Vssvc.exe and
vss_start.exe always run during the backup attempt, but vss_xp.exe starts and then terminates after a second or so
when Registry Backup is unable to successfully complete the backup. When a good backup is created, vss_xp keeps
running until the backup is complete.
Since I usually have a number of utilities and some other software running in the background, I've tried it with nothing
running except the OS itself and a couple of other essential things, but it still doesn't do the backup with VSS, and
nothing that's running in the background is new. It's all been there since long before the Registry Backup problem
started up.
I checked Log_Vss.txt, and it shows:
Creating shadow set {f334d3a4-8026-4f5f-99d4-cf88480d55b9} ...
- Adding volume \\?\Volume{2a06d9c0-cd01-11e3-ae2c-806d6172696f}\ [C:\] to the shadow set...
ERROR: COM call "m_pVssObject->AddToSnapshotSet((LPWSTR)volume.c_str(), GUID_NULL, &SnapshotID)" failed.
- Returned HRESULT = 0x80042317
- Error text: VSS_E_MAXIMUM_NUMBER_OF_SNAPSHOTS_REACHED
- Please re-run VSHADOW.EXE with the /tracing option to get more details
According to some research I did, shadow sets are not persistant on XP, so there's no way a set can last through a reboot, so how can the maximum number of snapshots ever be reached on XP if Registry Backup is scheduled for one backup per day?
