dd(1) just copies blocks. In whatever state they are in. Any data changing while your dd task is running will give you a low integrity backup. You will not be able to trust that you have a usable backup. Since you cannot ensure functional filesystems, another method for backup should be considered.
I recommend using dump(8) and restore(8), which are included with your OS. Missing data, such as log files that change, will still be missing, since you are backing up a live system.
If you have a database management system on that platform (PostgreSQL, MySQL, etc.) use the database's live backup facilities separately, since filesystem backup and restore will not ensure integrity of a database.
|