Xsan 2.3: Update to StorNext SNFS v4.2.1 controller to avoid data loss issue

Xsan 2.3 clients (running OS X Lion or Lion Server v10.7.2 or earlier) that access filesystems hosted by controllers that use StorNext SNFS version 4.2.0 may experience data loss when renaming files on StorNext-hosted volumes. A file may be unexpectedly deleted when renamed to a new name which differs only in the capitalization of the letters; for example, when changing "test" to "TEST".