Following configuration policy parameters are set on the Scalability :
DSM/Software Delivery/Shared/NOS: NOS-less agents attached = NO
DSM/Software Delivery/Shared/NOS: NOS-less on the fly = YES
If machine has problem to access to SDLIBRARY$ share, it switches automatically to NOS-Less method and send a message to Scalability Server requesting the download of zip file.
As "Nos-Less agents attached" is set to No, Scalability Server has not yet created the zip file but it should create it when it receives the message from agent.
But due to a problem with NASD settings it does not create the zip file and NOS-Less download method is failing too.