Volume restoration is NOT supported for a thin-provisioned RG.
The volume restoration does not guarantee the contents on the VDs can be completely restored. This special feature only helps to restore the RAID and volume configurations. Therefore it is possible that some data appear to be inconsistent when the RG/VD is restored from a deleted/failed status.
The volume restoration feature requires all the member disks in the historical time point to be present for restoring the RG/VD status. If any of the member disk is missing then it's not possible to restore the configurations. For further details about this restriciton and limiation please consult Qsan technical support team. 
No, the volume restoration only helps to restore the RAID/volume conifgurations, without modifying or impacting any block level contents inside. 
The volume restoration feature is a RAID and volume configuration status recovery utility. The feature helps to restore a RG and VDs on the RG to choosen historical points recorded in a volume coniguration records list.
If users have a missing features problem, please help to update the Qcentral firmware to the latest version. If the problem still remains after upgrading firmware, please contact with Qsan CS for the Qcentral feature request.
It will only occur on windows. It might be the Cache issue. Users can delete the Qcentral.key file and Qcentral.password file to fix this issue. The two files's path might be seem as"C:\Users\XXXXX\AppData\Roaming\QSAN\QCentral".
Yes, we always suggest the user to use the latest version. Because there are some bug might be fixed with the latest firmware. User can download the Qcentral and release note in our partner portal.
It is accordingly SLP(service location protocol) to scan for Qsan devices. When user start to scan for the devices, Qcentral will send the SLP packet to the host's broadcase domain, and then all the SLP clients which receive the SLP packet will re-send a service type's value to Qcentral. After that, Qcentral will list the clients which are corresponded with the service type's value.  The clinets which aren't corresponded won't list on Qcentral. 
Qcentral is JAVA based program(JRE), so it can support any OS which supports JAVA.