Incrbydate

An incremental-by-date updates the date and time of the last incremental at the server. If you perform an incremental-by-date on only part of a file system, the date of the last full incremental is not updated and the next incremental-by-date backs up these files again.

Important:

The last incremental backup time refers to the server time and the file modification time refers to the client time. If the client and server time are not synchronized, or the client and server are in different time zones, this affects incremental-by-date backup with mode=incremental.

The last incremental backup time refers to the server time and the file modification time refers to the client time. If the client and server time are not synchronized, or the client and server are in different time zones, this affects incremental-by-date backup and image backup with mode=incremental.

Both full incremental backups and incrementals-by-date backups backup new and changed files. An incremental-by-date takes less time to process than a full incremental and requires less memory. However, unlike a full incremental backup, an incremental-by-date backup does not maintain current server storage of all your workstation files for the following reasons:

• It does not expire backup versions of files that are deleted from the workstation.
• It does not rebind backup versions to a new management class if the management class has changed.
• It does not back up files with attributes that have changed, such as Access control list (ACL) data, unless the modification dates and times have also changed.
• It does not back up files with attributes that have changed, such as NTFS security information, unless the modification dates and times have also changed.
• It ignores the copy group frequency attribute of management classes.

Tip: If you have limited time during the week to perform backups, but extra time on weekends, you can maintain current server storage of your workstation files by performing an incremental backup with the incrbydate option on weekdays and a full incremental backup on weekends.