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Re: rack power question
by Alexander Harrowell 25 Mar '08

25 Mar '08

We'll need non-returns in there as well, to limit the maximum possible spillage. More seriously, the energy-efficiency community has a whole design approach for industrial facilities called "Factor 10 Engineering" which is about saving heat or cooling by using the shortest, straightest, fattest pipes you can at any point. You'd probably want to keep the flexible "water over ethernet" pipes to a minimum; have a pair of bigger risers per rack and tap into those. On Tue, Mar 25, 2008 at 3:14 PM, Christopher LILJENSTOLPE <cdl(a)asgaard.org> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Provided the brilliant tech didn't forget to remove the grit from the > connector on the pizzabox that then gets in the said valve and wedges > it open..... :) Remember folks, someone will always make "brighter" > remote hands.... > > In principal, though, I like it. > > Chris > > On 25 Mar 2008, at 06.08, Alexander Harrowell wrote: > > A valve in the connector; has to be pushed in by the other connector > > to let the water flow. Water pressure pushes it shut otherwise so it > > fails-safe. > > > > On Tue, Mar 25, 2008 at 12:35 PM, Leigh Porter < > leigh.porter(a)ukbroadband.com > > > wrote: > > > > That would be pretty good. But seeing some of the disastrous cabling > > situations it'd have to be made pretty idiot proof. > > > > Nice double sealed idiot proof piping with self-sealing ends.. > > > > -- > > Leigh > > > > > > -- > > Leigh > > > > Alexander Harrowell wrote: > > > I still think the industry needs to standardise water cooling to > > popularise > > > it; if there were two water ports on all the pizzaboxes next to > > the RJ45s, > > > and a standard set of flexible pipes, how many people would start > > using it? > > > There's probably a medical, automotive or aerospace standard out > > there. > > > > > > On Tue, Mar 25, 2008 at 12:23 PM, Leigh Porter < > leigh.porter(a)ukbroadband.com > > > > > > wrote: > > > > > > > > >> $5 > > >> > > >> > > >> Adrian Chadd wrote: > > >> > > >>> This thread begs a question - how much do you think it'd be > > worth to do > > >>> things more efficiently? > > >>> > > >>> > > >>> > > >>> > > >>> Adrian > > >>> > > >>> > > > > > > > > > > - --- > 李柯睿 > Check my PGP key here: > http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xCB67593B > > > > > -----BEGIN PGP SIGNATURE----- > > iQEcBAEBAgAGBQJH6RboAAoJEGmx2Mt/+Iw/O/UIAIEWSjeRr0mEcUNXoclxefEG > 4k7VjzoGLCBKlven62DwKXcFInBsGaaHXQyZH8vIKiraeh9JYFXo5wLotgO4bjYk > vV0l7Sd3iLpueDzFLbho3YWAcCh52dmLbZRn31L3/eSoNivagQKBruIy8WQmgJIt > 54/KiBIr7PUQXFYqA4kwiWnkOAZ+DfpGcfKY/LRhksGltVFW5N+X8FKSvlIR/ZjK > Ka+omSh2ccUNpD5Y6Iwa+KkAYulEnus5i1pzA07rz0YKxkIfXpPnadlMmdFJJiYo > wOqwIUVcjQQ2aruANKyXBnkWcTTD228xc06KgLLJToNjVY9XeOeJqQOxF6mNglc= > =+lj0 > -----END PGP SIGNATURE----- >

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Re: rack power question
by paul＠vix.com 25 Mar '08

25 Mar '08

forwarded with permission. > From: "Bob Bradlee" <Bob(a)BRADLEE.ORG> > To: "Paul Vixie" <Paul_Vixie(a)isc.org> > Date: Tue, 25 Mar 2008 11:16:17 -0400 > X-Mailer: PMMail 2000 Professional (2.20.2717) For Windows 2000 (5.1.2600;2) > Subject: Re: rack power question > > On 25 Mar 2008 06:17:15 +0000, Paul Vixie wrote: > > >this has been, to me, one of the most fascinating nanog threads in years. > > >at the moment my own datacenter problem is filtration. isc lives in a > >place where outside air is quite cool enough for server inlet seven or more > >months out of the year. we've also got quite high ceilings. a 2HP roof > >fan will .... > > Point taken, and I agree ... > > May I suggest we, make that the collective we, take all that extra floor > space that we don't have power for anywaydue to all the new blades servers > that need the cooling and put it to good use as a dust or (not so clean) > clean room to lower your cooling and cleaning costs. > > I worked on a project many years ago where "they" had built a big dust > collection room as an air scrubber for the computer room and some labs. > > Outside air and inside return air was brought in and mixed to an optimun > temp for the season at one end of a very long, very tall, very large, not so > clean, room sized dust collector they called the "clean room". On the far > wall was an array of low cost filters that fed the HVAC cold air return > path. > > Because the room was very large with a small inlet and a huge filtered > outlet wall. The air in the room stayed at a low pressure and was slowly > exhausted from the area at a very slow surface velocity. The vast majority > of the dust and just about all of the grit just fell out of the air onto the > floor where it could be cleaned up with a big shopvac or a snow shovel if I > had my way :-). > > Because most of the particulate matter hit the floor before it got to the > filters, the filter wall lasted many months vs the previous few weeks > between cleaning before the dust room was built. The "normal" filters in the > HVAC system had quality HEPA filters and rarely needed to be changed because > the air was being so well precleaned in the (not so) clean room long before > it ever got to the HVAC system. > > I was told me that what I was looking at was the second version, about twice > the cubic feet as the origional halway they first used. The filters now > lasted almost twice as long and they were moving much more air. > > The dust room I saw was very tall, I think 10 or 12 foot to the roof, it was > also very long over 30+ feet as I remember, but was limited to about 8 or 10 > feet wide (for other reasons). The filters used on the back wall were > designed to be used in the back wall of an auto paint booth and were low > cost and could be washed. Now that I think about it I expect the width was > determined by the size of the filter rack. I was told that before > remodeling, version one started as a long wide hallway that was off sealed > off and used as a big cold air return, using the old double doors on one end > as the "filter rack". I worked so well that when they remodeled, the hall > was widened and was opened up so that the cubic area of the low pressure > area could be maximized. > > What made it work was, the fact that small inlet vs a large outlet creates > low pressure in a large area. A long run of slow moving air in low pressure > will drop its dust and grit along the way, long before it gets a chance to > plugged up the filters. Think of it as a room size shopvac or a big Dysen > vacuum cleaner. :) > > I was told by the operator it worked better than he thought it would, and if > he was to build it again he would have wasted more floor space and made it > wider but could not justify the Sqfoot cost at that time. If he was > designing from scrach at todays energy costs, it would feed the whole > building not just the computer room and labs. > > He pointed out that while increased room height increased the cubic feet and > reduced pressure allowing more particulate to fall per SQfoot, increasing > the floor area was the same as increasing the effective filter area while > also reducing the static pressure in the room, win win. > > Bottom line, the bigger the better, make a dust room big enough you might > not need filters :-). > > Got a back room, you can seal up, or some unimproved space you can convert > into a home built open air scrubber ? > > I have seen it work ..... and it has been working for many years .... > Sorry I just can't tell you where, or I would have to kill you :-) > > Bob Bradlee > 614-xxx-xxxx > > PS. As I can not post to this list from this address, feel free to reply on > list if you think others might like to chime in.

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Mitigating HTTP DDoS attacks?
by Mike Lyon 25 Mar '08

25 Mar '08

Howdy all, So, i'm kind of new to this so please deal with my ignorance. But, what is common practice these days for HTTP DDoS mitigation during an attack? You can of course route every offending ip address to null0 at your border. But, if it's a botnet or trojan or something, It's coming from numerous different source IPs and Null0 routes can get very cumbersome. obviously. How do you folk usually deal with this? Any input would be greatly appreciated. Cheers, Mike

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Re: rack power question
by Patrick Shoemaker 25 Mar '08

25 Mar '08

Joe Abley wrote: > > > On 25 Mar 2008, at 09:11 , Dorn Hetzel wrote: > >> It would sure be nice if along with choosing to order servers with DC >> or AC power inputs one could choose air or water cooling. >> >> Or perhaps some non-conductive working fluid instead of water. That >> might not carry quite as much heat as water, but it would surely carry >> more than air and if chosen correctly would have more benign results >> when the inevitable leaks and spills occur. > > The conductivity of (ion-carrying) water seems like a sensible thing to > worry about. The other thing is its boiling point. > > I presume that the fact that nobody ever brings that up means it's a > non-issue, but it'd be good to understand why. > > Seems to me that any large-scale system designed to distribute water for > cooling has the potential for hot spots to appear, and that any hot spot > that approaches 100C is going to cause some interesting problems. > > Wouldn't some light mineral oil be a better option than water? > > > Joe > With IT systems, the equipment being cooled would likely reach thermal overload and trip offline before the cooling water could flash to steam. Of course a properly designed system would have relief valves anyway. One problem with mineral oil is the specific heat. Water has a specific heat of 4.19 kJ/kg-degC. Light mineral oil is 1.67 kJ/kg-degC. That means much higher mass flow rates (bigger pumps, tubing, more dynamichead loss, etc) for oil than water to transfer the same amount of heat. Oh, and if you want to see whether mineral oil burns, check out this video: http://www.youtube.com/watch?v=YZipeaAkuC0 (that transformer is filled with mineral oil). Sun has some good concepts going with its green datacenter initiative. Their approach of using extremely scalable power and cooling distribution systems that are customizable at the rack level allows for a wide variety of densities and configurations throughout the room. Check out the tour at this link: http://www.sun.com/aboutsun/environment/green/datacenter.jsp -- Patrick Shoemaker President, Vector Data Systems LLC shoemakerp(a)vectordatasystems.com office: (301) 358-1690 x36 mobile: (410) 991-5791 http://www.vectordatasystems.com

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Re: rack power question
by Paul Vixie 25 Mar '08

25 Mar '08

Matthew Crocker <mcrocker(a)crocker.com> wrote: > Seal off the room so you can control your replacement air source. Put a > series of cyclone dust collectors (think huge Dyson Vacuum) on your inbound > air. > > http://www.proventilation.com/products/ProductsView.asp?page=1&gclid=CKyD04… neat stuff. isc's neighbor has got one of these (for an industrial process). they are noisy, and not 100% duty cycle rated, but it's an interesting idea. > Then distribute your air through some electrostatic dust collectors > > http://www.dustcollectorexperts.com/electrostatic/ two of the ESP Disadvantages listed on that page are fatal in my application: o High initial cost o Materials with very high or low resistivity are difficult to collect however, this page also mentions "baghouse" filters, which i'd also heard in a private reply, and am now investigating. > Then run it through HEPA filters. :-). my servers don't have asthma. HEPA is hellishly expensive, annually, due to the number of filter replacements you need when the duty cycle is 100%. > How do you manage your humidity when you are pulling in 1% humidity 30 > degree air? It is more expensive to add water to the air then it is to cool > it sometimes. redwood city, california has signs over several streets leading to its oldtown that say (and i'm not making this up) "climate best by government test". what this appears to mean is, we have about three 30F weeks per year, and we have three four 100F weeks per year, and the rest of the time, it's between 50F and 70F, during which time the humidity is perfect for servers.

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Re: Mitigating HTTP DDoS attacks?
by Roger Marquis 25 Mar '08

25 Mar '08

Mike Lyon wrote: > So, i'm kind of new to this so please deal with my ignorance. But, > what is common practice these days for HTTP DDoS mitigation during an > attack? You can of course route every offending ip address to null0 at > your border. But, if it's a botnet or trojan or something, It's coming > from numerous different source IPs and Null0 routes can get very > cumbersome. obviously. How do you folk usually deal with this? Depends a lot on the size of the network. If it's more than a few colos I highly recommend Arbor Peakflow (http://www.arbornetworks.com/) Not cheap but it works and scales well. -- Roger Marquis Roble Systems Consulting http://www.roble.com/

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Looking for Clue at Earthlink
by Rob Szarka 24 Mar '08

24 Mar '08

If someone here is from Earthlink, or knows someone who is, please get in touch with me off-list. I have a mail-related issue to resolve. (Sadly the ARIN-listed contact is not valid and mail to postmaster seems to go into the same black hole as mail to abuse.) Specifically, the issue relates to the servers in 209.86.89.0/24, in case anyone here is already aware of an issue with the servers in this block and can help. -- Rob Szarka, Bizgrok Inc. http://bizgrok.com/ 860-887-5600 800-954-INET

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Re: rack power question
by Scott Weeks 24 Mar '08

24 Mar '08

----- eddy+public+spam(a)noc.everquick.net wrote: -------- PG> (We are not worried about cooling due to the special circumstances PG> of the space.) ixp.aq? ;-) ----------------------------------------------------- Back in 2000-2002 I exchanged email several times with a guy responsible for a (the?) datacenter in Antartica and funny enough they had heat problems there. scott

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Re: rack power question
by Lamar Owen 24 Mar '08

24 Mar '08

On Monday 24 March 2008, Robert E. Seastrom wrote: > Lamar Owen <lowen(a)pari.edu> writes: > > While this discussion might seem out of the ordinary for a network > > operator's group, it is a very good discussion. > > The sad part is the extraordinariness of discussions that are so > solidly on-topic as this one. Thanks for your contribution; I (at > least) really appreciate it. You're quite welcome. There is a whole 'nother side to this, too, especially for those who run DC power. The ampacity of conductors is quite a bit higher for DC; I have a copy of the best book on that subject, written by a telco engineer. Let's see: "DC Power System Design for Telecommunications" by Whitham D. Reeve, Wiley is the publisher. This is an expensive book; about $100 from Wiley; low price on Amazon right now is $75.75. This one goes over EVERYTHING when it comes to DC power distribution design and implementation. It was worth the price I paid, that's for sure. We have two 200A Lorains here, with A battery being 450Ah of C&D flooded cells, and B battery being a bank of 4 135Ah 12V sealed AGM batteries. Our core switches and all but one of our core routers have DC power supplies. Incidentally, all of this is fresh to me primarily because I'm in the process of building a new datacenter and moving our existing equipment into it, primarily for RFI mitigation reasons. -- Lamar Owen Chief Information Officer Pisgah Astronomical Research Institute 1 PARI Drive Rosman, NC 28772 (828)862-5554 www.pari.edu

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ARIN & CAIDA IPv6 Survey Is Now Closed
by Member Services 24 Mar '08

24 Mar '08

ARIN wishes to thank the 300+ people who completed the IPv6 survey. CAIDA will analyze the results and present them on 7 April during the ARIN XXI Public Policy Meeting in Denver. The results will be posted on the ARIN website in the IPv6 Information Center and on the IPv6 wiki at www.getipv6.info. ARIN thanks NANOG for the opportunity to announce the survey on its mailing list and appreciates the participation by many in the operator community. When available, ARIN will post a link to the survey results on the NANOG mailing list. Regards, Member Services American Registry for Internet Numbers (ARIN)

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