Z-DBackup is using the Volume Shadow Copy Service (VSS) of Windows for certain backup tasks in order to create a snapshot of a drive from which data is going to be backed up.

We have compiled a couple of possible solution in case you're experiencing problems with VSS or if a backup task fails because of the VSS. You should work through the solutions step by step and check if the problem still persists after every step.

Possible Solutions

0.Restart Windows.
Many problems resulting from services and VSS Writers can be fixed by rebooting the system.

1.Ensure that enough disc space is reserved for a shadow copy.
The drive a snapshot is taken from needs to have enough free space and at least 5% of the drive capacity should be reserved for snapshots (shadow copies).

2.Make sure that only one backup job using VSS is running at a time. Windows can only create one VSS snapshot per drive at a given time.

3.Deactivate other backup software that's using Windows VSS or that installed its own VSS-Provider.
 e.g. Acronis Backup, Symantec Backup Exec a.o.

4.Remove old VSS snapshots.
To remove old snapshots from all drive open the command line as administrator (Start + search "cmd" + right click "run as administrator") and run the following command.
vssadmin delete shadows /all

5.Check the status of the VSS Writers.
Create a VSS system information log file from within Z-DBackup by selecting the menu entry "System --> System information - VSS".

 

Check each VSS Writer entry (the entries beginning with "Writer name: ... Writer") for error messages. The last line of each VSS Writer entry should read "Last error: No error".

 

If one VSS Writer reports an error you should restart all services that have to do with VSS. This can be done by opening the program settings of Z-DBackup, selecting the tab "Lock" and clicking the button "Restart services".
 

0.If the VSS problems persist after step 6 you should search the Windows Event Viewer for VSS errors. The information and event ID found there can be used to search for the cause and a solution on the internet. You could for example search for "windows event id 22" if an error with the event ID 22 occurs.

0.Re-Register VSS and COM+ components.
Multiple commands have to be executed to re-register VSS and COM+ components. The simplest way to achive this is by creating a new *.bat file, copying the following commands in the *.bat file and executing the file as administrator.

Commands for 32bit and 64bit systems:

 

If the error still persists on a 64bit system after executing the above commands you should additionally execute the commands below.
 Commands for 64bit system:

 

0.If your system is running in a vitual machine it can help to reinstall the VM utility software.
Deinstall the VM's utility software, restart the VM and install the current version of the utility software for your VM (e.g. VMware Tools or Hyper-V Integration Services).

1.Windows Update.
Make sure that your system is up to date by installing all available Windows updates, hotfixes and service packs.

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