The screenshot below shows that the box knows when one of its drives goes missing.

Overview of installed drives in a RAID array, along with status changes

When drives formatted for FAT32 are connected to the SS4000-E everything looks normal. But one oddity that we discovered is that NTFS-formatted drives are recognized, but may not be used with this device. Unfortunately, no error message is thrown to indicate this situation when it occurs.

We also found that copying an 800 MB file using drag and drop in Windows Explorer led to a situation where Windows didn't show the typical copy activity display, even though the activity LEDs on USB-attached drives on this device showed that the process was underway. In fact, the Explorer window didn't react for about a full minute, after which it finally confirmed that the copy process was underway. After another couple of minutes, however, the status window announced that the target drive was unavailable!

Further testing revealed that this behavior occurs more frequently as file sizes increase - the larger the file, the longer it takes for Windows to recognize that the file copy is occurring. According to Intel, this is a known problem with the Linux version they used for this product. Unfortunately, this also means that we don't believe that extending the capacity of this device by adding USB-attached storage is a production-ready feature.

This happens when you copy a large file