Subject: Installing a UPS for a NetBSD server... software and procedures?
To: None <>
From: Gilles Gravier <>
List: netbsd-users
Date: 04/20/2007 08:20:16

OK... This night, I've had the last power failure that I want to hit my 
server. It took place while sup -s -v was doing its work, which means 
that the /usr/pkgsrc directory was corrupted when the machine died and 
that I had to manually fsck -y that partition before mounting it.

Since I didn't find a stable journalized filesystem for NetBSD (I'm 
still *VERY* open to suggestions on that one), I'm going to set up a 
UPS. Just one that supports one tiny server (i.e. 200 to 300W maximum) 
for say 10 minutes... nothing fancy. But I want the machine to be able 
to do a shutdown... and I want it to come back up by itself when power 

I have 2 questions about this...

1) What UPS work well with NetBSD? I see in the pkgsrc many pieces of 
code supporting UPS systems. What are your preferred ones? For what 
reasons? What package do you use to monitor the UPS and trigger the 

2) How does your UPS handle bringing the machine back up? My BIOS is 
configured so that on power outage, when power comes back up, the 
machine boots... but how does the UPS handle this? Since it's probably 
going to provide 220v to the power output for a long time if the server 
isn't drawing power from it, how does it trigger the reboot of the 
machine it's protecting?

Thanks in advance for your help,