rackmount DC power inverters?
I have no idea if this is on or off topic (apolgies if the latter). Right now we're running 48 1u servers in a cabinet off AC. We're considering switching to DC power supplies with the hope that any cost increase in the power supply and rectifier would be more than offset by the cost savings in electrical and cooling. So I'm looking for a rack mountable DC rectifier but since I've never shopped for one, I don't know good ones. Any help would be great. -- matthew zeier - But if you only have love for your own race, Then you only leave space to discriminate, And to discriminate only generates hate. - BEP
Re: Equinix Chicago Power Outage
Word is that they went back to utility power about 30 minutes ago and they're declaring the emergency over. On Sat, Jun 25, 2005 at 01:05:00AM -0400, Joel Perez wrote: I also lost connection to my equipment there. No official word yet either. From: [EMAIL PROTECTED] on behalf of Malayter, Christopher Sent: Sat 6/25/2005 12:51 AM To: nanog@merit.edu Subject: Equinix Chicago Power Outage Does anyone have any information as to what is going on at Equinix Chicago, other than a power vault a few blocks away catching fire. ERC has no information, we've had both AC and DC systems fail there. Any information is appreciated. Chris Malayter TDS Telecom - Network Services Data Network Engineering [EMAIL PROTECTED] Phone: (608) 664-4878 FAX:(608) 664-4644 --- Wayne Bouchard [EMAIL PROTECTED] Network Dude http://www.typo.org/~web/
Re: rackmount DC power inverters?
At 03:16 AM 6/25/2005, you wrote: I have no idea if this is on or off topic (apolgies if the latter). Right now we're running 48 1u servers in a cabinet off AC. We're considering switching to DC power supplies with the hope that any cost increase in the power supply and rectifier would be more than offset by the cost savings in electrical and cooling. Maybe I'm missing something, but I don't expect they will generate any less heat nor will your electric bill go down. Modern switching power supplies are very efficient. A DC power supply would either use a linear regulation circuit which is less efficient or using a DC-DC converter which is simply a switching power supply again to convert the -48VDC into the +/-5VDC and +/-12VDC needed by your servers internally. I suspect that if anything, the additional DC supplies combined with the loss in efficiency of the AC-DC-AC-DC conversion vs. AC-DC will produce more heat and use more electricity. Setup a DC power supply on the bench and setup an AC supply too. Measure the number of watts used in both cases. Make sure the computers are processing the normal workload. DC-DC converters rise from 40-50% efficiency to near 90% when they are at or near full design power output. The efficiency of the CPU, HDDs, etc. will remain the same so any variation is due to power supply efficiency differences. More power in with the same work out = more heat generated! Also factor in the efficiency loss of the DC rectifier you want to buy. If I am off-base here, I welcome any differing opinions. Matt, please let us know what your experiment tells you. -Robert Tellurian Networks - The Ultimate Internet Connection http://www.tellurian.com | 888-TELLURIAN | 973-300-9211 Well done is better than well said. - Benjamin Franklin
Re: Equinix Chicago Power Outage
On Sat, Jun 25, 2005 at 12:37:00AM -0700, Wayne E. Bouchard wrote: Word is that they went back to utility power about 30 minutes ago and they're declaring the emergency over. Now begins the fun process of pulling all the gear that got fried during the power surges. :) For a good link on the incident: http://www.belleville.com/mld/belleville/news/local/11981877.htm -- Richard A Steenbergen [EMAIL PROTECTED] http://www.e-gerbil.net/ras GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)
Re: [OT] network monitoring/visibility appliance
On 6/24/05, Daniel Golding [EMAIL PROTECTED] wrote: Just to ignore your wishes and reply on-list :) OK, I'll bite. (-: Other folks may be interested. The general area is known as route analytics. The box you are talking about may be from Packet Design (the HP solution is OEMed from them, I believe) or Ipsum networks. This is separate from modeling and simulation tools like Cariden, Opnet, and Wandl which all offer some greater or lesser degree of routing protocol support. After hitting send, of course, I came across both Packet Design's and Ipsum's product; neither of which are the manufacturer I had in mind. However they do perform the same functions. I believe the original idea for these boxes was to target service providers, but enterprises are also quite interested in the field, especially with the growth of RFC2547 VPNs. A box like this can help an enterprise keep track of the BGP advertisements and any OSPF/EIGRP redistribution at their sites (which can number in the thousands). The box I'm referring too was marketed towards MPLS, traffic engineering, and QoS visibility and monitoring. Had a handsome visualization tool as well. My personal opinion is that questions about Internet/WAN technology vendors on a _high_ level are perfectly appropriate for NANOG - at least as much as is xyz down? :) More in-depth stuff (how do I configure my GSR to dance the lambada) belong on the appropriate NSP lists... While I agree wholeheartedly, I started actively following NANOG less than a year ago, during which nearly every discussion had someone questioning it's relevance and on-topic-ness; which, frankly, was and still is, off putting. I apologize being so vague about all this - a fuzzy photographic memory is both a blessing and a curse. I don't remember the manufacturer, or what I was even looking for when I came across it. All I recall is a limegreen-ish box in the datasheet pdf; a mention of how, by being able to speak MPLS and it's ilk, the appliance didn't have to poll devices, nor was it a point of failure; and a strong focus on its traffic engineering and QoS visibility features. After looking at Packet Design and Ipsum, neither is the product I'm trying to rediscover. Many thanks for the off-list replies. If anyone has any clue what I'm referring too, on or off list replies are welcomed. Regards, aaron.glenn
