SonicWALL Webcam 6 Manual De Usuario

Actions that can lock the database and prevent the restore process include: 

Querying

Accessing by user or application

Opening Web Management Interface with database selected

Revisions may not appear immediately or even for some time due to a number of reasons 
including, but not limited to, large databases, single user mode databases, 24x7 databases, or 
other databases with high access frequency.