it's absolutly unprofessional from SWsoft to release such laking documentation regarding vzsnapshot.
1) when creating new OS template , there is no information regarding which directories and files need to be excluded from the os template.
2) regarding udev (and particularly udevd), there is no information if udevd need to be enable or disable while using vzsanpshot
3) regarding file systems which need to be excluded while using vzsanpshot
now , if someone will come and will say that OS template are unsupported and EZ Template is the supported method.
The answer for such argument will be: According to the documentation of Virtuozzo , in order to create a new EZ template , you first must have base template from the same distro you would like to build , which means if you would like to create a new EZ template of RedHat ES Version 4 then you first need base template = regular OS template of RedHat ES Version 4
And there is no reason for stopping the support for regular OS template.