The loopback settings provides source address overwrite feature for Syslog and SMTP traffic sent out from Qsan NAS units. In cases where the dedicated Syslog server or SMTP server only accepts a specific source address, user may choose to overwrite the source address of Syslog and SMTP traffic sent out from ALL ports. Please notice this setting only works for Syslog and SMTP traffic, does not apply to or impact any other data service types. 
The default gateway is used for all traffic originated from the Qsan NAS, such as SNMP, SMTP, NTP, Rsync, Rplication…etc. In cases where the destination IP address does not exist in the routing table, the system will then try to reach the destination via the default gateway, on the designated LAN port.
No the Qsan NAS will not automatically check for any new firmware upgrades.
The default username is ”admin”, and the password is “1234”.
A snapshot is a read-only connection of a file system or volume at a given point in time. Based on ZFS technology, a snapshot can be taken instantly without taking up too much CPU resource.
Yes, U1/U2/U3/U4/U6 all support multiple nodes. The number of nodes is 64.
The maximum number of U1 series local user/groupaccounts iare 4096/512. 
The maximum number of U2 series local user/groupaccounts are 10000/512. 
The maximum number of U3/U4/U6 series local user/group accounts are 10000/1024.
The Windows ACL is currently only configurable directly from Windows clients. Once enabled (in the share configuration page, select "enable ACL"), to make Windows ACL functions properly you'll have to set the POSIX layer ACL to "all pass" condition, which means setting the POSIX layer ACL to all RW permissions, and let Windows ACL work as the only ACL to filter the access from clients.
Currently CIFS/AFP/FTP use the same POSIX layer ACL and cannot be configured separately. WebDAV uses its own ACL set and NFS uses its own access rules, both independent from the CIFS/AFP/FTP ACL. 
You may register yourself on our Qsan partner portal and after successful registration you will receive notifications of new firmware releases from Qsan.
You may then enter the partner portal to download the firmware and upgrade it via Web UI.