Advanced

About JVM memory settings

ZipSnapNG by default allocates 512 megabytes as the maximum amount of memory it can use along its execution. This setting is usually safe for most of the deployments but if running a large backup job and a "heap space out of memory" error message is thrown or the system does not have enough memory, it is recommended to increase/decrease this value.

To do so, edit the conf/init.conf file and set the most appropriate JVM settings to vm.options.

About VSS integration

Even if ZipSnapNG does not natively integrate with Microsoft Volume Shadow Copy, it can read from a shadowed device passed as a parameter to the backup option.

In order to create a volume shadow device, a third party tool such as VShadow is required:
- VShadow Tool and Sample (https://msdn.microsoft.com/en-us/library/windows/desktop/bb530725%28v=vs.85%29.aspx)
- Volume Shadow Copy Simple Client (http://vscsc.sourceforge.net/)
- vshadow.exe versions (http://edgylogic.com/blog/vshadow-exe-versions/)

For example, if using VSCSC, the first step would be to instantiate a shadow copy device by running:

vscsc.exe -wait c:

Then copying the shadow copy device name out and running ZipSnapNG with it as an additional parameter to the command line:

ZipSnapNG config.txt backup \\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy4

Once the backup is completed press enter in the VSCSC window to close the shadow copy device.
VSCSC also provides a convenient way to run a script once the shadow copy is ready.