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Each time a VSS snapshot device is created, I attach a filter to that device object. When VSS snapshot is deleted, the remove device is called, and I am able to teardown my filter.
Now, if I enable System Recovery snapshots on a volume (C: for example), I see some strange behavior. I do not know if this is normal, or I need to address the issue. When our softwares VSS snapshot is created, everything seems to work as expected. However, after the IOCTL_VOLSNAP_DELETE_SNAPSHOT is detected, i never see the remove device for the snapshot device. I see the IOCTL_VOLUME_OFFLINE sent to the snapshot device, but the remove device is never recieved. Eventually, I can have hundreds of these device objects being filtered. What is even more strange, let's say I have 200 filters attached on a volumes snapshot chain because they are not deleted, when the system is rebooted, these 200 filter device objects are once again created and I attache. If I use various VSS tools after boot to peek into VSS via the APIs, I only see the snapshot created by System Recovery, so there are not 200 snapshots, only the two. But my filter attached to 200 device objects.
If I delete the system recovery snapshot, I will see all 200 device objects get their remove device calls.
Has anyone encounter this? I know there is a default of 512 snapshots. My may run up to the 512 and see what happens.
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