Don’t fail to backup files which are currently in use by other programs

Some applications open their data files exclusively and use them permanently. This prevents other applications, such as backup programs to read these files. As a result normally it is impossible to backup them.

However there are some ways to access HDD content on a lower level and still read files open by other applications.

Backup Platinum uses approach based on the VSS (Volume Shadow Copy Service) technology introduced by Microsoft in Windows XP. This technology is also present in MS Windows Server 2003 and Vista operating systems.

VSS provides the most reliable way to read open files. It does not only provide access to the content of an open file, but ensures that it is consistent. The usual problem is that the application that opened the file initially can continue modifying it at the time of backup. If the file is big, this can produce a situation when backup program reads a part of the file, then the application modifies it and after that the backup program reads the rest of the file containing modified data. As a result it backs up a part of an old version of that file and a part of its new version. The data contained in such backup is inconsistent and in most cases the whole process becomes useless.

VSS has two advantages that solve the problem described above. In the beginning of the backup process it creates an instant snapshot of a drive. This snapshot is not changed even if any files on that drive are modified during the backup process. This approach makes backup much more reliable.

Still there is a possibility that we make a snapshot at the moment when the data in the files is already inconsistent, because they are being modified. This problem can not be solved for all applications. However after VSS had been introduced several years ago many software vendors made their products VSS-ready. This means that for such applications the mentioned problem does not exist. If you backup data of a VSS-ready application, you can be 100% sure that the backup will be consistent and restorable.

A good example of a VSS-ready product is MS Outlook. This means that you do not need to close it to backup its data with Backup Platinum. This is useful, for example, if you schedule daily backups and do not want to close and restart your Outlook every day.