"A system and associated method restore a file system from incremental backups
in the presence of deletion, without restoring deleted files. This is accomplished
by logging deletions in a deletion log. Using the deletion log, the system re-deletes
the deleted files upon a restore operation to an incremental backup epoch. The
system the logs deletions so that the files that were deleted and survived a backup
epoch have their records logged. The activity log enables an incremental backup
from a prior snapshot, and represents a point-in-time version of the file system.
The system can either not restore the deleted files, or, alternatively, it can
restore the deleted files and then re-deletes them."