Using the ReadyNAS to create a Network UPS for PCs

super-poussin wrote:
Just a little Information : it will not work with duo

While it is true that the Duo GUI does not have this feature, it is still possible achieve the same capability with a little more work. The work-around requires changing some configuration files for the Nut service on the Duo. To do this you will have to have installed the SSH root login add-on, and know your way around a Linux file system.

The Nut daemon and monitor configuration files are located in /etc/nut, and can be edited to enable remote monitoring by a WinNUT client (or others). Two files need to be modified (upsd.conf and upsd.users). All disclaimers apply regarding modifications to your box as root.

First copy the original files to a safe place (don't get confused with the other similarly named config files in that directory),

mynas:~# cd /etc/nut
mynas:/etc/nut# cp upsd.conf upsd.conf.original
mynas:/etc/nut# cp upsd.users upsd.users.original

Then modify upsd.conf to allow remote access to the UPS daemon. I added the two lines that contain reference to "mynet". Note, I opened it up to the entire 192.168.1.0/24 subnet. You could be more specific if you only want to allow a single PC to access it, and that PC has a static IP address (mine uses DHCP).

mynas:/etc/nut# cat upsd.conf
ACL all 0.0.0.0/0
ACL localhost 127.0.0.1/32
ACL mynet 192.168.1.0/24

ACCEPT monitor localhost
ACCEPT monitor mynet
REJECT all all

Now you have to create an authenticated user by modifying the upsd.users file to add an arbitrary user ("pcuser" in my case). The "allowfrom" directive has to match the ACL you created in upsd.conf above. Note the PC is a slave since it will take direction from the Duo that is actually connected to the UPS. Strictly speaking, you could re-use the "monuser" authentication, but I preferred to create one specifically for the PC.

mynas:/etc/nut# cat upsd.users
[monuser]
password = pass
allowfrom = localhost
upsmon master
[pcuser]
password = your_pass
allowfrom = mynet
upsmon slave

Then all you have to do is tell the upsd daemon to re-read it's configuration file (or reboot the Duo).

mynas:/etc/nut# upsd -c reload

At this point, your remote client (e.g. WinNUT) should be able to contact the Duo and read the status of the UPS. Note, you have to configure the PC client with the same user ("pcuser") and password ("your_pass") that you configured here. For the WinNUT client it would look like this (assuming your Duo is at 192.168.1.2),

MONITOR UPS@192.168.1.2 1 pcuser your_pass slave

I'm not sure why Netgear chose to leave this capability out of the Duo GUI (probably a marketing decision), but I can report that it works well for me after a little hacking.

Safe computing :)
Craig