All backup-related operations either create new files or reference existing files underneath a specified directory that holds backup data, referred to as the backup directory in this manual. Choose in advance for this directory a location on a file system with sufficient storage, which could even be remotely mounted from a different server. You specify the path to this directory with the --backup-dir option for many mysqlbackup commands.
Once you establish a regular backup schedule with automated jobs, it is preferable to keep each backup within a timestamped subdirectory underneath the main backup directory. To make mysqlbackup create these subdirectories automatically, specify the --with-timestamp option each time you run mysqlbackup.
For one-time backup operations (for example, when cloning a database to set up a replication slave), you might specify a new directory each time, or, for a single-file backup, specify the --force option to overwrite the old backup file.