Is there any special recommendations to use a shared network storage like minimum bandwidth or throughput?
The QlikView Server Manual only refers about :
"QlikView supports a SAN (NetApp, EMC, etc.) that is mounted to a Windows Server (2003 or 2008) and then shared from that server. Storage presented to a server via a SAN must appear as locally attached storage."
There can be issues with the read/writes to the PGO files on a slow network. Is this a cluster? If not the best thing you can do is keep your root folder local for the PGO files and then mount a folder for your documents.