I will be rebooting servers early Saturday morning, shortly after midnight. The server which houses home directories will be rebooted possibly more than once.
Most of the servers will be rebooted to load a new kernel.
The server housing the home directories will also be testing a new microcode package from Ubuntu to see if it has corrected a problem with the 6850k multiplier register. If the package performs properly there will be only one reboot of that machine, if not a second reboot to back out the new code will be required.