Microsoft fixes security vulnerability in volume shadow copy service

When using backup software such as Langmeier Backup, which offers the option of backing up drives during operation, administrators should check the version of the operating system. Microsoft has fixed a bug in various operating system versions that can lead to defective backups.

The company has published a knowledgebase entry and provided updates that fix a bug in Windows Vista SP2, Windows 7, Windows Server 2003 SP2, Windows Server 2008 SP2 and Windows Server 2008 R2 that can cause backups to be corrupted during operation with the Volume Shadow Copy Service (VSS) under certain circumstances: http://support.microsoft.com/kb/2748349

These errors have already been fixed in Windows 7 and Windows Server 2008R2 with Service Pack 1, but users of older versions should apply the updates quickly. The error should occur if a partition is larger than 8 GByte and the size is also exactly a multiple of 8192 MByte; the error also affects extended partitions. As a result, individual files in the backup may be faulty. The Windows updates fix the problem.

Urs Langmeier, Managing Director and developer of the Langmeier Backup solution, explains: "A backup can only be carried out without errors if a system is also running without errors. In the case of defective hard disks or unstable drivers, the backup solution receives incorrect data from the operating system and then properly saves this data away." However, the backup copy then contains unusable data. "Langmeier Backup can of course check the data after the backup. However, when used during operation, data may have been changed between the backup and the verification," adds Langmeier. "Therefore, the results of the check must be evaluated accordingly: Was this file being edited and may therefore differ from the backup copy?" Urs Langmeier also recommends that all users of the software install the available updates.