reading Datadomain OS release notes made my day:
When performing a DD OS upgrade using a USB key, make sure the USB key is inserted slowly into the Data Domain system’s USB socket. Two criteria can help you to judge how “slowly” to insert the key:
The LED on the USB key starts blinking after you’ve inserted the USB to the very end or, for a USB key with no LED display, make sure it takes more than one second to fully insert the USB key.
I assume this will be the next step:
Please fondle the hardware while doing the upgrade…

