Which files are backed up

When you request a backup, the client backs up a file if certain requirements are met.

To back up a file, the client must meet the following are the requirements:

• The selected management class contains a backup copy group.
• The file meets the serialization requirements that are defined in the backup copy group. If the copy group serialization parameter is static or shrstatic, and the file changes during backup, the file is not backed up.
• The file meets the mode requirements that are defined in the backup copy group. If the copy group mode parameter is modified, the file must have changed since the last backup. If the mode is absolute, the file can be backed up even if it does not change.
• The file meets the frequency requirements that are defined in the backup copy group. The specified minimum number of days since the last backup must elapse before a file is backed up.
• The file is not excluded from backup by an exclude statement.
• The file is not excluded from backup by the operating system. These excluded files can be found in registry subkey HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BackupRestore\FilesNotToBackup.

Files that are part of the Windows system state are eligible for backup only when the system state is backed up. You can back up the system state only as a single entity because of dependencies among the system state components. You cannot back up or restore the files individually. For example, because C:\windows\system32\ntoskrnl.exe is part of the Windows system state, it is not backed up during an incremental or selective backup of the C:\ drive.