Re: [Soekris] thermal problem general crashes ?
On Tue, 13 Dec 2011 15:24:31 +0100 Frank Schuhmann f.schuhm...@t-online.de wrote: At their website soekris is telling something about for what the boxes are to use: 1. Small net services 2. Small routers / servers / vpn / wlan I'm using my net5501 as a router. And as i said, WLAN crashes the machine. So i'm using it in a way that is not expected??? What is with the wm (milliwatt) power of the WLAN card? Dont know. But these devices usually have less than 1W peak. Too much, let the device turning quickly to hot? Definitly not. It's in a constant air stream. Err... I'm not sure i understand you correctly... But, if you really have a full lightning strike on your alix/soekris box and have the case melting... then the molten metal is the least of your problems as anyone near the box will be already dead. Beside, that the iron sheet of the soekris box will melt as well. No aluminum cases in business installs please, in some or few cases this is perhaps ok, but not usual. Drilling a little hole at the back side of the soekris box to connect an electric ground cable from the soekris box to the rack will prevent the soekris box from smelting, but not an aluminum case. Er.. get yourself a better phyiscs book. This wire will not protect anything from melting. The wire will evaporate long before the case even gets hot, due to much higher electrical resistance. The reason why metal cases are earthed is to prevent them from building up electrostatic charge and in case the device inside is faulty and has a mains short circuit to the case. And a little math to prove my point here: Assuming we have a light alu case of 100g weight, it will take about 54kJ or 54kWs to get the case to melting temperature (ie it is still hard). Any wire that conducts that much energy will be long evaporated before the case gets to that temperature. And mind you, it needs another 40kJ to melt the case. And even assuming you can melt the case just with an lightning strike and not fry everything around it, then there is still the aluminium oxide layer which will hold the molten aluminum together until it melts itself (at about 2000°C) Several meters to open a windows, to let the smoke out only was be done by a wet t-shirt over the face. The metal plated server cases were in one part, sure with electric fire marks at some places, but the both aluminum cases were looking like toasted bacon with smelted cheese on the boards. Nearly the whole device structure was totally damaged, the rack door windows were spread out all over the room, ok it was a secure window only little but very sharpen shards were going over the whole room. That rather sounds like the lightning strike caused a little fire that burned something inside the rack. And if you get that far and your automatic fire extinguisher doesn't properly work (given you have one), then it's not the fault of the case. Nobody was working in this room (only for server racks and too cold to work la long time in) If you made other experiences, you are perhaps a lucky one. Not anymore lucky, then lucky enough to work at companies who value the security of their employees enough to have proper earth connections on everything and every cable comming from outside is passing trough a lightning arrestor. For the metal case based hardware the insurance will pay but not for the aluminum cases, ok later they were paying also for this because the electric prevention installation was made false (not deep enough inside the ground at the outside of the building!!! Perhaps in other countries there are other laws and house or environment insurance and they are paying even all, likes in the country you are acting and working. You live in germany, you've the same regulations as we do in switzerland. And that the lightning rod was not earthed properly is definitly a big issue and cannot be blamed on any alu case. And i doubt that the insurance company will not pay due to the use of aluminum cases. If it there would be a risk of melting of alu cases, then there would be a regulation for this. And i'm not aware of any. In the contrary, there are even lightning arrestors sold that use aluminium cases. How could they work if the case would melt at the smalest hit? http://www.radiolabs.com/products/antennas/accessories/lightning-protection.php Anyways.. i dont belive you that the case melted due to the lightning strike directly. Especially not if you are telling me that a steal case would not have melted. If this incidence is true, show us some pictures. Trust me or not after this event, nobody 50 - 80 km around Hannover will tell you it is a good choice to store a aluminum based case inside a business network environment for a very long time. I know a few sysadmins from the Hannover area. Nobody has heard of this incident. Last but not least Attila let me tell you that my English is not very well formed and is purely wide distances
Re: [Soekris] thermal problem general crashes ?
On 20.12.2011 11:32, Attila Kinali wrote: No aluminum cases in business installs please, in some or few cases this is perhaps ok, but not usual. Drilling a little hole at the back side of the soekris box to connect an electric ground cable from the soekris box to the rack will prevent the soekris box from smelting, but not an aluminum case. Er.. get yourself a better phyiscs book. This wire will not protect anything from melting. He might have a point, though. Proper grounding and a case able to magnetically shield things (such as iron) can make all the difference between the electronics surviving or not. Of course not at the point that the case melts :) -- Stano ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] thermal problem general crashes ?
No aluminum cases in business installs please, He might have a point, though. Proper grounding and a case able to magnetically shield things (such as iron) can make all the difference between the electronics surviving or not. Direct lightning strike to will kill electric equipment anyway, put it in steel, aluminium case or wooden box. No difference. Sorry. Some of net5501 instabilities are related with case bad thermal design. If you have a choice - aluminium case (which can melt with strike :-) ) with better cooling characteristics or steel case (which can melt too, but simply at 1400 C, twice of aluminium melting temperature), but makes your equipment unstable due to cooling issues, then which case you prefer? How probable is direct lightning hit, which can make equipment case melt? Steel cases are cheaper, so maybe this is Soekris decision thriving force, i don't know. -- =Alvar= ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
Re: [Soekris] thermal problem general crashes ?
Fanless computer systems are tricky to keep cool. I have a little computer around here somewhere (can't find it at the moment though) which has a rubbery (silcone?) block that fits between the processor chip and the case - presumably thermally conductive and electrically insulating. Anything that can provide a good thermal path from the hot items inside the case to the case inner surface would reduce the peak temperatures quite a bit. The case, being larger than the chip, spreads out the heat transfer and would not get as hot as the chip. Some of the newer PC cases and motherboards include 'heat pipe' technology to carry the heat from hot spots to finned heat sinks which can get rid of the heat. Perhaps one of these gadgets could be found or made to fit the Soekris cases. Old laptops are sometimes cooled during charging by standing them on end so the air circulates better around the hot bottom. Attention to how the Soekris case is mounted could help in this way (with internal heat path augmentation). Hope this helps. Let me know as I have a 5501 (somewhere around here). Bob G On Tue, 2011-12-20 at 22:43 +0200, Alvar Kusma wrote: No aluminum cases in business installs please, He might have a point, though. Proper grounding and a case able to magnetically shield things (such as iron) can make all the difference between the electronics surviving or not. Direct lightning strike to will kill electric equipment anyway, put it in steel, aluminium case or wooden box. No difference. Sorry. Some of net5501 instabilities are related with case bad thermal design. If you have a choice - aluminium case (which can melt with strike :-) ) with better cooling characteristics or steel case (which can melt too, but simply at 1400 C, twice of aluminium melting temperature), but makes your equipment unstable due to cooling issues, then which case you prefer? How probable is direct lightning hit, which can make equipment case melt? Steel cases are cheaper, so maybe this is Soekris decision thriving force, i don't know. ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
[Soekris] thermal problem general crashes ?
Hi List, sorry first for aswering not in a short time, but for this and the other messages I was asking three other peoples first, from them I know exactly one is using not only one net5501 and only on work!!! Example 1: A Security administartor working in a greater insurance company. Many (20 - 25) net5501 with an GB LAN Port PCI card as snort sensors for Host based IDS (Servers) and Network IDS (Switches) The boxes are still placed in a closed up rack in a climated server room (0 till +2 Celsius) Only one PSU were replaced till today. One CF card must also be changed, but this is not couting, because soekris is not the producer! The other both opinions, I will show up in the next post, to much and to long so I will split the posting. At their website soekris is telling something about for what the boxes are to use: 1. Small net services 2. Small routers / servers / vpn / wlan With low power consuming parts. All parts soekris were producing, I mean all the lan and all vpn cards are using low power and dont overheating the soldered on chips from the cards and the boards. Now perhaps some people (surely like me too) were thinking that the cards we insert in, are also using low power, but the chips are overheating or the chips are heating to much the air inside the case. And in my opinion it dosen´t matter that we opend the case, because if a chip is to hot, he is to hot, point. So in my opinion soekris is selling hardware for they descript it on their homepage. An Intel Pro 1000/GT Desktop adapter as a WAN port many, many people use with their net5501 and they don´t flooding the list with their problem, because they have to find out by themselves what is to hot and what runs smooth on the machine. If I´m informed right their are more then 20.000 sold boards and boxes and I think it must be connected to the hell, that only you got two boxes they are malformed or tuched by this error. And if so, why one of this boxes was running with an uptime till over a year? Most forums I view from time to time or have a look in are filled with thoose messages, but never, I repead, never in direct context with the soekris produced lan and vpn cards, even with other low power, but overheating cards or too many services. At this point also it is not unusual thoose people (also likes me, Alvar Kusmar and many other) are having a look to other producers like MikroTik or PC Engines (Alix). But Soekris is also offering on their homepage also custom made cases made from different materials and there are also from other vendors and traders like www.yawarra.com.au and http://soekris.kd85.com. Alix - solid aluminium cases For smal routers or firewalls amd only at home use please. If an electrical strike hits the building or 19 rack, the aluminium cases will smelt in seconds and spread out, if the rack is not closed with a front door, very hot liquid aliminium. This can harm human beings and other devices. And to prevent the employees and devices from damage is also perhaps a administrative job. To store this aluminium cases in professional network enviroments or infrastructures not to be recommend, and this only in my opinion. - Not able to store a hdd inside - only 256 MB of ram - No pci slot MikroTik - metal plate based cases For professional use or also called productive network systems. Hard and software came from one company under one direction and a under one concept. No overheating problems but also not the range and so many options like the other both above delivering and serving. Those chips that can be going hot, because the machine is hard in use are sorted with an passive heat sink and some of their wlan routers give you the abbility to insert 1 - 5 wlan cards and no thermal problem. - Training for the os is expensive - dont let you use much more hardware - not so many services like other delivers ! - stable and compatible to all supported hardware - prof. support - each system needs a licence that must be paid Soekris inc. - Solid metal plate based cases For all, having fun, playing, testing, home use, office use and professional use. From the day he was soldering the first boards in his living room at home till today the company was growing up and also the boards became more powerful. The company is selling boards, cases, lan and vpn cards and supports much operating systems and many, many other hardware. - for each level of need and use - low power using - spare parts from own production - nice price - more ram like alix - more powerful then the most MikroTik devices So in my opinion only the overheating parts like cards from other vendors are the usual suspects in this game. __ Hinweis von ESET NOD32 Antivirus, Signaturdatenbank-Version 6693 (20111208) __ E-Mail wurde geprüft mit ESET NOD32 Antivirus. http://www.eset.com ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com
Re: [Soekris] thermal problem general crashes ?
On Thu, 8 Dec 2011 14:35:22 +0100 Frank Schuhmann f.schuhm...@t-online.de wrote: At their website soekris is telling something about for what the boxes are to use: 1. Small net services 2. Small routers / servers / vpn / wlan I'm using my net5501 as a router. And as i said, WLAN crashes the machine. So i'm using it in a way that is not expected??? With low power consuming parts. All parts soekris were producing, I mean all the lan and all vpn cards are using low power and dont overheating the soldered on chips from the cards and the boards. Those parts were bought from soekris directly. So i assume they have been tested with the net5501, as they have been sold as accessories for the net5501. Alix - solid aluminium cases For smal routers or firewalls amd only at home use please. If an electrical strike hits the building or 19 rack, the aluminium cases will smelt in seconds and spread out, if the rack is not closed with a front door, very hot liquid aliminium. This can harm human beings and other devices. Err... I'm not sure i understand you correctly... But, if you really have a full lightning strike on your alix/soekris box and have the case melting... then the molten metal is the least of your problems as anyone near the box will be already dead. Beside, that the iron sheet of the soekris box will melt as well. And to prevent the employees and devices from damage is also perhaps a administrative job. No, this is actually a job for the architect and electrician. They have to ensure that no lightning strike can enter the building w/o passing trough some absorbers. Any strike that you get trough the power cable, telephone or network sokets is still high enough to fry your electronics and give you a severe shock. But it shouldn't be able to kill you. Much less to melt any metal case. To store this aluminium cases in professional network enviroments or infrastructures not to be recommend, I dont see any reason why aluminium cases should not be used in professional enviroments. I'd rather say that you mix up something. Attila Kinali -- The trouble with you, Shev, is you don't say anything until you've saved up a whole truckload of damned heavy brick arguments and then you dump them all out and never look at the bleeding body mangled beneath the heap -- Tirin, The Dispossessed, U. Le Guin ___ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
