Updating global snapshot files
If you enter Time Machine when your backup disk isn't available, Time Machine automatically uses local snapshots to help you restore files.
Reconnect your backup disk to make even more backups available.
It keeps an additional snapshot of your last successful Time Machine backup until space is needed.
Thresholds specified as a negative number represent the maximum number of uncovered entities allowed.In the MDS, we generate snapshot-representing dentries as part of the regular process for flushing them.Dentries with outstanding Inode with multiple hard links is moved to a dummy global Snap Realm.The dummy Snap Realm covers all snapshots in the filesystem.The inode’s data will be preserved for any new snapshot.