eho@clarity.princeton.edu (Eric Ho) (07/08/90)
This is just a suggestion -- perhaps somebody at Sun's Server Group might want to at least start planning to add support to the kernel and in SunOS in general so that it can interact with *temporary* power backup devices. By temporary, I mean those boxes that will kick off automatically when the voltage coming from the wall/floor socket drops below a certain threshold and it'll supply power from its batteries until its own juices run out or the power from the wall comes back up above the threshold. I think that every future large servers sold by Sun should somehow incorporate such temporary backup devices -- both to protect disk drives and to warn other users & systems -- this is particulary important in a large setup where you've lots of drives attached to the server. Very often, the power outage only lasts for a brief moment (as in a thunderstorm for instance) and will come back up to normal -- and this means that the disk drives will come online and offline like a yoyo -- not too good for the drives even when they've autoparking arms. The kernel/SunOS support mainly would log such events in /var/adm/messages and do auto-shutdown if the voltage from the wall socket remains dead/low for more than say 5~10 minutes -- thereby giving enough time for users & other systems to finish off before its batteries run out. The device also should be able to send warning interrupts to the kernel when its batteries are low -- e.g. it has "served" several brief power blackouts. This assumes the device is able to switch when the voltage coming from the wall is back to normal again hence saving battery juice. When the batteries are low, sysadmin people should be notified and if they still don't change batteries then the next blackout will be a permanent auto-shutdown no matter how brief it is - hence guarantee that there will always be enough batteries juice for any blackouts. One can get those boxes where the batteries last for less than say 15 minutes thereby reducing cost. Oh well, ... I wonder if anyone in the Server Group might do something about this. Eric Ho Princeton University eho@clarity.princeton.edu