While NE40 had been running for a long time, after that when we wanted to get into harddisk to collect some information or trasfer file, but unfortunately we could not detect the harddisk in the master board even actually it's existing in that board.
At the first time, I wanted to plug out the board to check that what happened to that board. But after I switched over the slave board to be active, I saw that after the master board that has been switched over to be slave board come up, then at this time we could see the harddisk on that board.
Maybe the hardware itself has some bugs or because it's running such a very long time, then the error occured and it caused harddisk unaccessible.
R&D or some responsible person for hardware or software of NE40 should find the root cause of this problem, since if this situation happens we can explain the reason to our customer clearly. But if anyone faces with this problem, we just switch over the board then everything will back to the normal condition.