<div dir="ltr"><br><br><div class="gmail_quote">On Sat, Aug 15, 2009 at 7:26 AM, Amos Shapira <span dir="ltr"><<a href="mailto:amos.shapira@gmail.com">amos.shapira@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
2009/8/14 Micha Silver <<a href="mailto:micha@arava.co.il">micha@arava.co.il</a>>:<br>
<div class="im">> shimi wrote:<br>
>> Sample the UPS unit for "how much battery time left do you have?" and<br>
>> initiate automatic shutdown when the number falls below the 5 minutes<br>
>> threshold ?<br>
>><br>
> Yes, that's probably best. Thanks. The disadvantage is that after the power<br>
> comes back, someone has to physically go to power-up the servers.<br>
<br>
</div>Well, that's how UPS's are supposed to be used.<br>
<br>
In addition to Wake-On-Lan mentioned by Shimi, there are also:<br>
1. Boot on AC power - i.e. if the AC power comes back then start<br>
reboot. That's a BIOS setting.</blockquote><br>Which assumes a power loss after the automatic shutdown. According to Murphy law, and to my experience, power tends to return 1 minute before the battery gets completely drained, just for me to wonder "why oh why did I shut down my whole server room, it would have survived". Of course that if I wouldn't have shut down everything, the outage would be 1 minute longer. :)<br>
<br>So still need WoL :) (to be initiated by the machine sampling for the UPS remaining battery after the battery managed to re-charge for additional few minutes of backup power - enough for a second power up and shutdown of everything assuming a second outage...)<br>
<br>-- Shimi<br></div></div>