[X4U] mac mini hooked to a TV

[David Ledger]

At 18:15 -0400 4/4/09, Dave wrote:
>That is excellent!
>
>With all due respect to your local electrical supply, a UPS is a 
>small investment when compared to the cost of all the equipment 
>connected and the associated data. Considering that a UPS can 
>protect your equipment from surges, voltage spikes, under-voltage 
>(brown-outs), and short term power outages, any of which could 
>easily damage electronics or corrupt data, I can't understand why 
>anyone wouldn't have all their electronics protected.

The electrical supply in urban Europe is of a high quality. It is 
regulated (electrically and legally) to  tolerances than mean 
equipment is safe. If out of range problems do damage equipment, it 
is either an insurance matter or a claim from the supplier. I've 
worked for a company that was on the edge of town and made claims 
both ways. The installed supply capacity to the area was insufficient 
in that rare case. The same should apply to domestic supply, but it 
might take more argument.

As you look at a conceptual increase of supply reliability/quality, 
there comes a point where a UPS is more likely to fail than the 
supply. I've come across UPS failure causing the problems rather than 
preventing them. You have to judge where in the graph you are. In 
server rooms it's normal to have dual power supply computers, with 
one fed from a UPS that provides a supply round the whole room or 
building (usually backed up by a generator); the other fed from a 
smaller UPS for that machine alone, it being fed from an alternate 
supply rather than the big UPS. That protects from supply failure and 
from UPS failure.

On a list like this I've heard of someone who wouldn't have a UPS 
near his systems because of the damage caused when at least two 
failed consecutively.

David


-- 
David Ledger - Freelance Unix Sysadmin in the UK.
HP-UX specialist of hpUG technical user group (www.hpug.org.uk)
david.ledger at ivdcs.co.uk
www.ivdcs.co.uk