Hi I have a Dell PowerEdge T310 *tower* server.. I have to buy an ups by apc... anyone could help me giving an hint ? a simple "smart ups 1000" could be enough ? thx so much!! lewis.
On 4/14/2011 12:06 PM, admin lewis wrote:> Hi > I have a Dell PowerEdge T310 *tower* server.. I have to buy an ups by > apc... anyone could help me giving an hint ? > a simple "smart ups 1000" could be enough ?APC's website has a "UPS Selector" feature that will recommend a UPS based on your equipment. -- Bowie
On Thu, Apr 14, 2011 at 5:06 PM, admin lewis <adminlewis at gmail.com> wrote:> Hi > I have a Dell PowerEdge T310 *tower* server.. I have to buy an ups by > apc... anyone could help me giving an hint ? > a simple "smart ups 1000" could be enough ?It depends on how long you want it to run. Your choice is a small UPS to give your server just enough time to shut down or a big UPS to allow you to carry on working for some time. In general a fileserver will only need a minimum of 5 to 10 minutes to shut down as your workstations are probably already dead. Obviously this has changed now that people have laptops. If you're running big processes on the server then you need long enough to let them complete or shut down gracefully. Of course this assumes reliable power. If you regularly have outages or bad brownouts then scale up.
Kevin Thorpe wrote:> On Thu, Apr 14, 2011 at 5:06 PM, admin lewis <adminlewis at gmail.com> wrote: >> Hi >> I have a Dell PowerEdge T310 *tower* server.. I have to buy an ups byapc... anyone could help me giving an hint ?>> a simple "smart ups 1000" could be enough ? > > It depends on how long you want it to run. Your choice is a small UPS togive your server just enough time to shut down or a big UPS to allow you to> carry on working for some time.And it depends on what you're trying to deal with: if it's occasional brown or blackouts, or power flickers (let's not talk about Chicago, for example), then you need enough power to provide all it will draw for a couple minutes at most. If you're looking at longer power outages, you'll need something a lot bigger, though one suitable for the above purpose would usually allow it to shut down gracefully; it's not like Linux takes a long, long time to shutdown. <snip>> people have laptops. If you're running big processes on the server thenyou need long enough to let them complete or shut down gracefully. Heh. Depends on your definition of "big processes", says the guy whose users normally are running jobs that run for *days*, if not weeks. mark
Partially echoing what was already said: - Stick to APC - Avoid the low end "workstation" models like the plain BackUPS. As a minimum get a BackUPS-Pro. SmartUPS are better. - Use the sizing app on the APC web site - Careful of your mains power. Besides what was mentioned for generators, accidentally chaining an APC UPS into AC provided by a server room UPS can kill the downstream UPS. - For controlled shutdowns on battery exhaustion, check out apcupsd. - Decide whether your UPS will power one server or a few. If you're powering a few, decide whether the control is master-slave (which you can do with a serial/USB cable to the master, then network to the slaves), or if you need the more expensive setup where the UPS talks directly to multiple servers. I think the former is fine (as long as your network switches are on the UPS), but ymmv. Devin
On 04/14/11 9:06 AM, admin lewis wrote:> Hi > I have a Dell PowerEdge T310 *tower* server.. I have to buy an ups by > apc... anyone could help me giving an hint ? > a simple "smart ups 1000" could be enough ? > >apc smartups or eaton powerware woudl be my choices. 1000VA should be fine. avoid consumer UPS's like apc backups, they are junk. how long do you need the system to stay powered when the power fails? just long enough to shutdown? or do you need it to stay up for some period of time?
On Thursday, April 14, 2011 02:51:02 PM John R Pierce wrote:> switched PC/Server PSU's *so* don't give a bleep about sinusoidal power, > its not funny. first thing they do is full wave rectify the power to > DC, then they run that DC through a high frequency (several 100Khz > usually) oscillator and into a toroidal transformer. they would be > perfectly happy running off a full squarewaveActually, a squarewave with the same RMS as a sine wave will full-wave rectify and filter to a lower DC voltage than the sinewave. The supply may or may not be able to deal with that. To work the math, 120Vac RMS yields a peak voltage for a sinewave of about 170V (Vpeak=Vrms*square-root-of-two); full-wave rectified and filtered that gives 170V DC (with some ripple, depending upon the size of the filter capacitor relative to the current drawn); a squarewave at 120Vac RMS yields a peak voltage of 120V, and a filtered DC of 120V, equal to the filtered DC for an input RMS AC voltage of 84Vac RMS (for a sinewave, Vrms=Vpeak/square-root-of-two); if your power supply can deal with that..... Also, the odd-order harmonics may create their own havoc in the filtering. So, no, there's more to it than meets the eye. I are a EE; degree and all..... :-) But if you don't believe me, please look at: http://www.opamp-electronics.com/tutorials/measurements_of_ac_magnitude_2_01_03.htm and come back later....
On Thursday, April 14, 2011 02:55:51 PM John R Pierce wrote:> http://powerquality.eaton.com/Products-services/Backup-Power-UPS/5125.aspx > or similar for this application. I'd take one of those up versus the > same size APC SmartUps any day.We have a 5KVA Best Ferrups here that has never worked correctly.... :-) But I've seen my share of toasted APC's, too. Currently we run older APC SmartUPS (pure sine) for the workstation stuff and Symmetras in the Data Centers. Looking to put in a Toshiba or similar 500KVA in the secondary Data Center later in the year.> BTW, another thing the 'good' UPS's do, more important than 'pure > sinusoidal output' for computer purposes*, is buck/boost voltage regulation.Yes.> * if you're running audio gear off a UPS, you definitely want the > sinusoidal output, but thats another market entirely.Or old 3Com Corebuilder/CellPlex 7000 gear, which shuts down with anything but pure sinewave.....