I remembering being at a data center on a hot summer day. Power went out, generator started. Things were fine... then all the air conditioners switched on at the same time. Actually stalled the generator. We had to put sequencers on the AC.
From: Faisal Imtiaz Sent: Saturday, May 14, 2016 9:20 PM To: [email protected] Subject: Re: [AFMUG] Data center temperatures FYI, Electrical Code (NECA) and most datacenters require the power not to be loaded beyond 80% of breaker capacity... i.e. 16amp draw on a 20amp circuit. Additionally, one also has to have head room on the power circuit to deal with start up draw (current rush). It's not pretty when you have a crap load of servers starting up all together :) Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] -------------------------------------------------------------------------------- From: "Eric Kuhnke" <[email protected]> To: [email protected] Sent: Saturday, May 14, 2016 7:50:22 PM Subject: Re: [AFMUG] Data center temperatures How does a 44U cabinet need 208V 60A for storage arrays? In a 4U chassis the max hard drives (front and rear) is about 60 x 3.5"... Say each drive is 7.5W TDP, that's 450W of drives. Add another 200W for controller/motherboard and fans. 650W in 4U. 44 / 4 = 11 Multply by 650 7150W More realistically with a normal amount of drives (like 40 per 4U) a single 208 30A is sufficient, 208 x 30 = 6240W Run at max 0.85 load on the circuit, so 6240 x 0.85 = 5304W In a really dense 2.5" environment all of the above is of course invalid, you could probably need up to 7900W per cabinet Then there's 52U cabinets as well... On May 13, 2016 6:16 PM, "Paul Stewart" <[email protected]> wrote: Yup … general trends on new data centers are pushing those temperatures higher for efficiency but also with better designs .. One of our data centers runs at 78F and have no issues – each cabinet is standard 208V 30A as you mention but can go per cabinet much higher if needed (ie. 208V 60A for storage arrays) From: Af [mailto:[email protected]] On Behalf Of Eric Kuhnke Sent: May 11, 2016 5:15 PM To: [email protected] Subject: Re: [AFMUG] Data center temperatures There have been some fairly large data set studies done shown that air intake temperature for huge numbers of servers, at 77-78F does not correlate with a statistically significant rate of failure. http://www.datacenterknowledge.com/archives/2008/09/18/intel-servers-do-fine-with-outside-air/ http://www.datacenterknowledge.com/archives/2012/03/23/too-hot-for-humans-but-google-servers-keep-humming/ how/what you do for cooling is definitely dependent on the load. Designing a colo facility to use a full 208V 30A circuit per cabinet (5.5kW) in a hot/cold air separated configuration is very different than 'normal' older facilities that are one large open room. On Wed, May 11, 2016 at 1:58 PM, Ken Hohhof <[email protected]> wrote: I’m not sure you can answer the question without knowing the max heat load per cabinet and how you manage airflow in the cabinets. AFAIK it used to be standard practice to keep data centers as cold as possible without requiring people to wear parkas, but energy efficiency is a consideration now. From: That One Guy /sarcasm Sent: Wednesday, May 11, 2016 3:51 PM To: [email protected] Subject: Re: [AFMUG] Data center temperatures apparently 72 is the the ideal for our noc, i set our thermostat to 60 and it always gets turned back to 72, so i just say fuck it, I wanted new gear in the racks anyway On Wed, May 11, 2016 at 3:46 PM, Larry Smith <[email protected]> wrote: On Wed May 11 2016 15:37, Josh Luthman wrote: > Just curious what the ideal temp is for a data center. Our really nice > building that Sprint ditched ranges from 60 to 90F (on a site monitor). I try to keep my NOC room at about 62F, that puts many of the CPU's at 83 to 90F. Many of the bigger places I visit will generally be 55 to 60F. Loads of computers (data center type) are primarily groupings of little heaters... -- Larry Smith [email protected] -- If you only see yourself as part of the team but you don't see your team as part of yourself you have already failed as part of the team.
