UPS for network
- We have a problem that has been periodic and ongoing. Finally this week we
think we may have figured out the culprit.
We have an 8 computer network. Four SLC provided computers, one donated
and three recently purchased used from a local company. It is those three
that have been causing problems. They are Dell Optiplex 150 (from memory,
I'll have to double check). We have had them about six months and almost
from the beginning one of them would periodically reboot itself either in
the middle of being used or when just sitting there idle. In the past
month, the other two of the same type have started doing the same
thing. It is very sporadic. Some days they'll work fine for hours and
other days they reboot over and over again until we turn them off. They
are not all plugged into the same electrical outlet.
I had been at a loss as to what might be causing this problem. Virus,
spyware, faulty power supply, ??? A few days ago I reported to our
maintenance people that one of our electrical outlets was losing
power. That particular night it had been on for two hours, then I noticed
everything plugged into it wasn't on. It was out for an hour or so and
then all of a sudden we noticed it was working. (The power strip plugged
into it had been left on.)
They told me they had been having electrical problems in the building where
they temporarily lose power in parts of the building. This all fell into
place as we were discovering it wasn't just our one computer having
problems. We had also had a hard drive die in one of these computers. It
hadn't crossed my mind until that night that it was due to the power surges
of shutting off and turning on constantly. (I know, I should have known
Anyway, they are working on the electrical problem as I write. We
discovered a second wall outlet with no power last night. And, the one
across the room is still not working. But, in the meantime the higher ups
have agreed to let us purchase UPS's for the computers to prevent any more
damage. My problem - I don't know what to look for, where to start.
Some questions -
Should I limit the number of computers we have on at a time until they get
this all resolved?
How do I determine what "size" UPS to purchase?
Am I better off having one for each computer or can I plug multiple
computers into one if it is high enough for the equipment plugged into it?
What else should I be aware of in this situation?
Thanks for any input on this. We are open all day tomorrow (Sat.) and I'm
wondering if I should keep the computers off (or at least the three that
recycle) until I get some UPS units. We aren't 100% positive this is our
problem, but it sure makes sense from what we've been told is going on in
- Well, I thought the previous version of this thread was final, sigh. One hopes that your workstations are always shutoff by normal process and also that abnormal shutdowns are few and far between. But, no, being shutoff by abnormal processes is not particularly more dangerous that normal shutdowns. If it were, the systems in my FHC would constantly be in trouble. Our staffers shutdown improperly fairly regularly (by accident).The only thing that happens differently is that normal shutdowns close system processes in an orderly fashion. The hardware doesn't know the difference. Absence of electrons is absence of electrons. What can happen is that a process that is using a data file and holding it open may not get closed cleanly, leading to a possible corruption of that file. UNIX based operating systems is very susceptible to abnormal shutdowns and designed to run continuously. But we are 'blessed' with Microsoft OS's which self-destruct regularly without any interference. So in this regard, they are hardier to abnormal shutdowns. People wouldn't but Microsoft if it was as touchy as UNIX. We'd be using Apple-soft or CPM instead.The only other thing that happens by regular shutdowns (hardware-wise) is what is called thermal cycling. The hardware warms up then cools off at every startup and shutdown. This is not a problem because hardware manufactures design their hardware to withstand millions of thermal cycles before they reach their mean-time between failure (MTBF), which means their average life is in the tens of years (specifically speaking about hard-drives). Since PC hardware is replaced before ten years (hopefully), thermal cycling should not be a problem. Remember 75 MHz, Pentium 1 & 2 processors are only about ten years old.Aside from the occasional 'weak' piece of hardware which fail before their time, voltage spikes, and related EMF/RFI, electrical problems, your hardware should be obsolete long before their useful life.Bill H.
Patty Gaddis <geneamom@...> wrote:Thanks, Bill. Yes, I have gotten a lot of response. It has been very helpful.
You stated you don't connect your workstations. Isn't having them shut off
and turn on not through the normal process deadly to the components inside
if done a lot? We lost a hard drive in one of these computers. One day it
just wouldn't boot up from the hard drive. I assumed it was due to this
power drop/surge problem.
And, yes, I am hoping that just the electrical problem being resolved will
eliminate this problem. But, the director has a UPS at his home (although,
he admits he doesn't really know how to use it) and he'd like them at the
At 06:50 AM 12/12/2006, you wrote:
>Boy, have you gotten a response on your UPS issue. Most everything I've
>heard is good advice. You choice is largely a matter of money and
>location of components. My FHC has a 900VA UPS for the server and its
>monitor. Everything else is protected with EMF/RFI protected power
>strips. The server is the only system I really want to protect. If the
>workstations shutdown and have to be restarted, I don't care. They are
>rebooted everyday anyway. While upgrading the network I connected a
>second (backup) server, printserver, printer, and 15-port switch to the
>UPS. Unfortunately everytime someone tried to print something the UPS
>overloaded and shut everything off. 900VA was not enough for the load I
>gave it, so I removed everything except the essentials and have no
>problems now. APC is a good brand, they have been in the business for the
>10+ years I've have been and Admin. There are a couple of others, but I
>don't recall the names at the moment. Check the Internet for reviews
>regarding UPS' and the ways to use them.
>Once you get a clean bill-of-health concerning the power to your building,
>a lot of your problems will probably disappear.
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