Here’s the final installment of our 4-part SIS series:
Because SIS creates reparse points from identical files, backup programs must understand this capability of the NTFS file system in order to efficiently backup and restore these files. SIS includes the Sisbkup.dll module to support backup/restore applications. For information about processing requirements for backup and restore applications, see the Microsoft Platform SDK Web site (http://go.microsoft.com/fwlink/?LinkId=51846).
The backup tool that is included with Windows 2000 Server and Windows Server 2003, Ntbackup.exe, handles these files properly.
Using a backup application that does not support SIS
If a backup program is not aware of SIS files, it would make duplicate copies of the SIS files in the actual backup data file. When restored, they would create normal files instead of the reparse points. The SIS groveler would eventually combine these files, but possibly not in time to prevent the restore operation from running out of disk space.