如果下一个记录层的用户数据的记录开始位置预先知道，在用户数据记录之前，在下一个记录层上形成保护块。

If a record start position of the user data is learned beforehand in the next recording layer, the guard block is formed on the next recording layer prior to the recording of the user data.

youdao

请记住，由于记录ID是系统创建的域，所以无法在用户数据库之间移植id。

Remember, since the record ID is a system generated field, there is no way to transfer IDs between user databases.

youdao

您可以使用tar来创建一个系统备份，该文件系统将压缩到一个可记录的DVD上，然而，现在大多数系统的用户数据非常庞大，一个DVD不能存下。

You may be able to use tar to create a system backup that will fit on a recordable DVD, once compressed; however, most modern systems have enough user data that a single DVD won't hold it all.

youdao