UPS failure modes

Jack Bates jbates at
Fri May 30 00:21:08 UTC 2003

nicholas harteau wrote:
> We run a configuration similar to this, except we do failure per-row
> with one APC Symmetra supporting between 3 and 6 cabinets, depending on
> the projected load.  In the past 2.5(?) years, we've had one controller
> failure that did not cause an outage.  All the batteries are fine,
> though we have not run them to zero.  It turned out to be a very clean
> install as far as conduit and cabling goes, we're very happy with it.

We do the same for one of our data centers, except we borrow one of the 
telco generator trucks due to lack of facility for an onsite generator. 
We have it setup to power both our Symmetra's as well as the telco's 
battery array one floor up. We've replaced two batteries and one 
powersupply in about 4 years (all recent) and had the Symmetra panic and 
warm reboot when electricity was being rerouted once.

The warm reboot was interesting. It reboot every APC MasterSwitch and 
90% of our routers. 10% of our routers and all servers stayed live even 
though their MasterSwitch's reloaded firmware. Go figure. I wouldn't 
have minded except that the Cat had been up for over 3 years without a 
reboot and I really wanted someone onsite when that took place. :)


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