I'm certain that there is a very elementary answer to the question above but I have not been able to find the answer thus far. I see the drive activity light flashing but I don't know what other computer(s) are reading from or writing to the FreeNAS (9.10.2) server. I would like to upgrade from U2 to U3 and presume that a reboot may be needed. I don't want to interfere with any writes going on at this time. How can I determine what devices are reading from or writing to the CIFS share? What generally happens if writes are underway when a reboot of the NAS is initiated? Will the device writing to the NAS generally keep trying until the FreeNAS server again becomes responsive?