Please press the reset button on the front panel, and the IP setting and password will be reset to factory setting.
Or we have the white paper you can download it on the Qsan partner portal to reset the password.
The volume snapshots will be stored in the pool, but user needs to be careful the snapshot usage of the pool capacity. And filesystem will be stored in the share foler as hidden folder, so it may produce so many invisible folders under the root share folder.
For all series QSAN NAS, the maximum number of LUNs that the user can create are 256. 
1. The user private data will be stored in the userhome pool as user's exclusive folder. 
2. The user quota is applied for the user's folder capacity in the UserHome.
If the system is running stably, we would not suggest you to perform the firmware upgrade on your Qsan storage. With every new firmware download there is always a relese notes that comes with the firmware for you to check if the update or enhancement is necessary on your system, you may then decide whether the upgrade is necessary or not.
Please find the serial console cable in the accessories box, and connect the host to Qsan NAS console port with the console cable provided. The user can checks or changes the setting on the system via console interface. More information of serial console setup please see the white paper-How to use the serial console.
** For U1 series, there is only VGA output for displaying console messages.
The max number of U2/U3/U4/U6 is 4096. U1 is 2048.  
Yes, users can attach multiple LUNs to the same volume. But we will suggest users to attach multiple LUNs in the cluster environment or in share storage environment. If attaching multiple LUNs to serveral servers without the cluster/sahre storage environment, the data would be corrupted. 
No, the user quota only can be used in the UserHome. The user quota is applied for the user's folder capacity in the UserHome. 
You may have to check the release notes that comes with the firmware for checking if any companion software need to be upgraded. At the end of the release notes there's a list of which companion software versions have to be used with the firmware.