Nut upsuser - May 2012 - Two servers with redundant supplies on two UPSs

Scenario:

* Two windows 2003 servers (different models)
* Each server has two PSUs
* Each server has a single serial port
* Two UPSs are available of the exact same type (XPower Tigra 1kVA). 
Each has a serial port
* The 1st PSU of each server is powered by the 1st UPS
* The 2nd PSU of each server is powered by the 2nd UPS

I am trying to install NUT on the best "optimal" way for these two 
systems. My obvious solution so far is:

Implementation 1:
* Connect 1st ups via serial to 1st server and 2nd ups via serial to 2nd 
server
* Setup nut on both systems on standalone mode.

I'd obviously prefer a clean master-slave relationship, but since each 
server has a single serial port, I can't do that. Any better ways to do 
this? Just asking :)

Thanks again for your time.

With kind regards,


Michail.-

Hello,
Am Donnerstag, den 10.05.2012, 11:09 +0300 schrieb Tmima Pliroforikis
Perifereiakis Enotitas Pierias:
> 
> * Two windows 2003 servers (different models)
> * Each server has two PSUs
> * Each server has a single serial port
> * Two UPSs are available of the exact same type (XPower Tigra 1kVA). 
> Each has a serial port
> * The 1st PSU of each server is powered by the 1st UPS
> * The 2nd PSU of each server is powered by the 2nd UPS
> 
> I am trying to install NUT on the best "optimal" way for these
two
> systems. My obvious solution so far is:
> 
> Implementation 1:
> * Connect 1st ups via serial to 1st server and 2nd ups via serial to 2nd 
> server
> * Setup nut on both systems on standalone mode.
> 
> I'd obviously prefer a clean master-slave relationship, but since each 
> server has a single serial port, I can't do that. Any better ways to do
> this? Just asking :)
See
http://www.networkupstools.org/docs/user-manual.chunked/ar01s06.html#BigServers
for some implementation hints

So if you set up both servers beeing the master for one UPS and
monitoring both with "minsupplies 1" that would do the trick. So
Server
1 is master for UPS 1 and slave to server 2/UPS 2; Server 2 ist master
for UPS 2 and slave to server 1/UPS 1.

You should not forget to have a redundant power supply on the network
switch between these two servers as well or maybe a direct network cable
connection between both servers.

(I once had servers running until the ups powered off, because the
server runnung nut master was the only one shut down correctly. The
others lost connection to nut because one of the switches was not
connected to the UPS)

Kind regards,
Ingo
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: Dies ist ein digital signierter Nachrichtenteil
URL:
<http://lists.alioth.debian.org/pipermail/nut-upsuser/attachments/20120510/106c2915/attachment-0001.pgp>

Hello Ingo,

your comments were most appreciated, especially the following:

Ingo Schaefer wrote:
> You should not forget to have a redundant power supply on the network
> switch between these two servers as well or maybe a direct network cable
> connection between both servers.
>
> (I once had servers running until the ups powered off, because the
> server runnung nut master was the only one shut down correctly. The
> others lost connection to nut because one of the switches was not
> connected to the UPS)
I have a switch which takes its power from the first UPS, so the setup 
is definitely not symmetrical here.

Thanks again for your kind comments.

BR.-