VIA PC3500 board revives old eMachines PC

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Last September one of my desktop machines died and I bought a new Windows 7 machine to replace it. Today I brought it back to life again by transplanting a motherboard from an old case that I had been using as my previous Linux server. The replacement board is a VIA MM3500 (also known as VIA PC3500), with a 1.5 GHz VIA C7 CPU, 2 GB of DDR2 RAM and on-board video. It still has two IDE connectors as well as two SATA connectors, allowing me to use both my old DVD and parallel ATA HD drives, as well as newer high capacity SATA drives.

After the motherboard swap I had to reactivate Windows XP because it detected a major change in hardware. Most of the hardware of the new board worked immediately, I could boot and had Internet access without any reconfiguration. When I started with the new machine. I just had to increase video resolution from the default 640×480 to get some dialogs working.

I then downloaded drivers for the mother board and video from the VIA website. I now have the proper CN896 (Chrome IGP9) video driver working too.

When I tested the board as a server with dual 1 TB drives (RAID1), it was drawing 41W at idle. Running in my eMachines T6212 case with a single PATA hard drive it draws 38W at idle.

Before removing the old motherboard I made a note of all the cable connections on both motherboards. The front-mounted USB ports and card reader have corresponding internal cables, which connected to spare on-board USB connectors. The analog sound connectors connect to the motherboard too. The only port at the front left unconnected was the IEEE-1394 (FireWire / iLink) port, which has no counterpart on the VIA board.

It feels great to have my old, fully configured machine with all its data and applications back thanks to a cheap motherboard that works flawlessly.

Fukushima had new vents, but system failed

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The New York Times reports that the reactors at the Fukushima 1 nuclear power plant were equipped with an improved system for venting steam in an emergency, but it failed to work. Originally it had been reported that TEPCO did not retrofit the units that had been online since 1970s with the new designs introduced in the US in the 1980s. However, it appears to have done so between 1998 and 2001.

The problem was, the improved system relied on the same sources of electricity to operate valves as the cooling system, so when the cooling system stopped working as diesel generators failed and dangerous levels of steam pressures built up, the venting system designed to protect the containment wasn’t working properly either. Instead of one system protecting the public if the other system failed, both had a single point of failure, their dependence on diesel generators in the flooded turbine hall basements.

The executives did not give the order to begin venting until Saturday — more than 17 hours after the tsunami struck and six hours after the government order to vent.

As workers scrambled to comply with their new directive, they faced a cascading series of complications.

The venting system is designed to be operated from the control room, but operators’ attempts to turn it on failed, most likely because the power to open a critical valve was out. The valves are designed so they can also be opened manually, but by that time, workers found radiation levels near the venting system at Reactor No. 1 were already too high to approach, according to Tokyo Electric’s records from the accident’s early days.

At Reactor No. 2, workers tried to manually open the safety valves, but pressure did not fall inside the reactor, making it unclear whether venting was successful, the records show. At Reactor No. 3, workers tried seven times to manually open the valve, but it kept closing, the records say.

The results of the failed venting were disastrous.

Reactor No. 1 exploded first, on Saturday, the day after the earthquake. Reactor No. 3 came next, on Monday. And No. 2 exploded early Tuesday morning.

The venting system could also have been damaged by the earthquake.

According to the NYT, the new venting system bypasses filters that hold back much of the radioactivity.

When TEPCO was talking about venting the reactors, before the spectacular hydrogen explosions, they reassured the public that the release of gas would be “filtered”. Either they were misleading the public, or they were talking about the old venting system, which was suspected of not being able to cope with the pressure of an emergency release, which is the very reason the new system had been introduced.

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Fukushima cooling system switched off 10 minutes after quake

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Data released by TEPCO on May 16 shows that apparently the isolation condenser, a cooling system that is supposed to protect the reactor after a shutdown, was manually shut down in unit 1 within 10 minutes of the earthquake.

When the quake hit at 14:46 on 2011-03-11, the power station lost its grid connection. Diesel generators sprang into life to provide backup power for the Residual Heat Removal System (RHR). Around 15:00 someone manually shut down the isolation condensor. About half an hour later tsunami hit the station. Within minutes the diesel generators failed and the RHR stopped. At that point the battery-operated pumps for the isolation condenser were the only system still able to remove heat from the reactor core, but the valve for this system had been closed by operators. From that point onwards the reactor core was entirely without cooling. Records show that at 18:10 the valve was open again. At 18:25 it was closed again and 21:30 it was open again. The isolation condenser finally failed at 01:48 on 2011-03-12, perhaps because its batteries ran out.

According to the AREVA presentation from 2011-04-07, the isolation condenser in unit 1 stopped at 16:36 on 2011-03-11, but perhaps that was based on incomplete or bad data from TEPCO.

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Fukushima reactor damaged before tsunami

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According to a Kyodo news report, extremely high radiation levels were measured in unit 1 of Fukushima 1 nuclear power station the night after the quake, hours before radioactive steam was first vented from the containment vessel at 04:00 the next morning (2011-03-12).

Workers entered the No. 1 reactor building during the night to assess the damage only to hear their dosimeter alarms go off a few seconds later, sources at Tokyo Electric Power Co. said. Since they thought the building was filled with highly radioactive steam, the workers decided to evacuate.

Based on the dosimeter readings, the radiation level was about 300 millisieverts per hour, the source said, suggesting that a large amount of radioactive material had already been released from the core.

The source of the steam was believed to be the No. 1 reactor’s overheated pressure vessel.

But for that scenario to hold, the pressure in the reactor would have to have reached enormous levels — damaging the piping and other connected facilities. It should have taken much more time to fill the entire building with steam.

A source at Tepco admitted it was possible that key facilities were compromised before the tsunami.

(Japan Times, 2011-05-16)

According to the AREVA presentation by Dr Matthias Braun, the reactor isolation condensor in unit 1 stopped working at 16:36 on 2011-03-11, 55 minutes after the diesel generators had been knocked out by the tsunami. After that, pressure from boiling water built up in the reactor pressure vessel, from where it was vented into the containment via water held in the pressure suppression chamber.

It was only when pressure in the containment had built up far beyond its design limit that steam was first vented from it at 04:00 on Saturday, March 12. Radiation levels of hundreds of millisieverts per hour in the building hours before that suggest that steam from the pressure vessel or containment escaped hours before it was supposed to have come out.

Direct seismic damage to pipes, valves or other components from the quake at 14:46 is a plausible explanation for a premature radiation release while the containment was supposedly still serving its function of holding back radioactivity from the environment. The local intensity of the quake was either close to or in excess of the design specification the reactors had been built to. For example, maximum seismic acceleration at unit 3 was measured at 507 gal in East-West direction, versus the 441 gal it was designed for.

So how does it matter if parts of Fukushima prefecture became uninhabitable because of broken steam pipes or because of flooded diesel generators? Isn’t the outcome the same? It’s actually a very important difference: Nuclear power companies in Japan are now taking measures to evaluate tsunami risks in plants around the country. Units 4 and 5 of Hamaoka NPP in Shizuoka were recently shut down because they’re located right on top of a quake fault line, but the plan is to restart them around 2014, after tsunami defenses have been beefed up around them. The problem is, even if — thanks to raised sea walls — the diesel generators were not knocked out by sea water, but the violent shaking were to destroy some other vital part of reactor such as cooling pipes, the outcome could still be the same.

Unit 4 blown up by leak from adjacent unit 3

The Wall Street Journal reports that TEPCO now think the hydrogen explosion that destroyed the service floor above the spent fuel pool in unit 4 was caused by hydrogen leaking from the adjacent unit 3, which also exploded:

Tepco also released its analysis of a hydrogen explosion that occurred at unit No. 4, despite the fact that the unit was in maintenance and that nuclear fuel stored in the storage pool was largely intact.

According to Tepco, hyrogen produced in the overheating of the reactor core at unit 3 flowed through a gas-treatment line and entered unit No. 4 because of a breakdown of valves. Hydrogen leaked from ducts in the second, third and fourth floors of the reactor building at unit No. 4 and ignited a massive explosion.

Adjacent units 3 and 4 are connected, for example by sharing a venting tower for the release of radioactive gases, which is located between them.

Nuclear expert Arnie Gundersen believes it is plausible that the particularly violent explosion that destroyed the top of unit 3 may have involved a criticality event (i.e. a chain reaction) triggered by the well-publicised hydrogen explosion.

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TEPCO’s new cooling plan for Fukushima 1

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After finding no water at all in the section of the reactor core of Fukushima 1 unit 1 that normally holds the fuel rods but instead finding 3000 tons of leaked water in the basement of the unit, TEPCO has abandoned its original plan and come up with a different plan to cool the reactor core.

Instead of trying to raise the water level inside the light bulb-shaped containment that surrounds the pressure vessel, which has not succeeded, it will spray water on to the reactor pressure vessel from above. The water will be pumped from the basement of the reactor, into which it appears to have been leaking and where it currently stands 4 m deep. It will be decontaminated to make it less radioactive before being recycled for cooling. A water decontamination unit built for TEPCO by French nuclear company AREVA is expected to arrive on Tuesday.

Reactors to be covered under tents

Meanwhile TEPCO has announced plans to cover units 1, 3 and 4 under tent-like polyester fabric sheets supported by a steel frame. The reactor building of unit 2 did not suffer a hydrogen explosion and therefore does not need covering. The tents may make it possible to filter radioactive steam and other emissions still rising from the reactor buildings whose cores are still beyond the boiling point and whose spent fuel pools are being cooled through water evaporation. Before the structure can be erected the vicinity of the blocks needs to be cleared of debris to make space for cranes and other construction equipment.

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Uphill struggle to cool Fukushima 1 unit 1

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After pumping increased amounts of water into the reactor core of Fukushima 1 unit 1 with the aim of bringing it to a “cold shutdown”, TEPCO had to conclude that the water level in both the reactor core and the containment is much lower than expected and their plan appears not to be succeeding.

Previously it was believed that the lower half of the fuel rods in the reactor pressure vessel (RPV) was covered in water. Now it appears that part of the RPV is dry and the fuel rods (or what’s left of them) are fully exposed. However, due to the damage to the rods much of the uranium pellets inside may already have spilled into the bottom portion of the RPV and may thus receive some cooling after all. TEPCO had only recently revised its estimate of core damage for unit 1 down from 70% to 55%.

The plan to provide ouside cooling to the RPV by flooding the dry well of the containment surrounding it with enough water to raise the water level to above the top of the fuel rods has not worked yet. Even after pumping more than 10,000 m3 of water, the water level in the 7,400 m3 containment is still below half, not even reaching the bottom of the RPV, let alone its top.

If the water level doesn’t rise further because of leaks then it seems quite unlikely that it will be possible to repair those leaks using manual labour, especially at dose levels of 10 millisievert and more per hour. Even when it looked like the plan might work for unit 1, it was questionable if the same procedure could then be applied to unit 2 or 3, which were already assumed to have a leaky containment.

TEPCO has not yet discussed any alternative plan if flooding the containment won’t work for some or all of the units.

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TEPCO sends workers into unit 1 of Fukushima I

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TEPCO has taken the first step towards installing new heat exchangers in wrecked reactors at its Fukushima 1 nuclear power plant that have suffered core damage after a cooling system failure. The objective is to achieve “cold shutdown”, which means that cooling water in the reactor remains below 100 degrees C and the pressure is at atmospheric level. Currently the water inside units 1, 2 and 3 is still boiling.

During normal operation, sea water cools steam coming out of the power turbine that generates electricity. It condenses it back to water, which goes back into the reactor core to be turned into setam again. After a shutdown, electric pumps and a separate heat exchanger, known as the residual heat removal system (RHR), take over the core cooling function. TEPCO had been aiming to restore the RHR since about March 20, when it reestablished a grid connection into the turbine hall, but found that the pumps are no longer usable.

The new system will not cool the core directly, which after the fuel rods partially melted is highly contaminated, but instead will circulate water to the containment vessel that surrounds the core, cooling the central part of the reactor from the outside rather than from inside. To that purpose, water will be pumped from a pipe connected to the containment to a heat exchanger, which passes the heat to an external water cycle that will be cooled using air. The original cooling system depended on sea water for condensing steam in the inner cycle, but the sea water intake system was flooded and destroyed by the tsunami, along with most of the diesel generators that provided power to all emergency pumps.

Before any work can be performed inside the reactor building, which no human had entered since the hydrogen explosions around March 12-15, the level of radiation there has to be brought down considerably. To that purpose a pair of hose pipes has been laid through the airlock and hooked up to a filter. Until at least May 16 air will be pumped through a filter set up outside the building. US-made robots sent into units 1 and 3 measured radiation levels of up to 49 mSv/h in unit 1 and up to 57 mSv/h in unit 3 on April 18. The dose inside the airlock of unit 1 was 270 mSv/h, in unit 3 it was 170 mSv/h. The typical background radiation dose for a civilian is 2-3 mSv per year. TEPCO hopes to be able to reduce radiation inside the building by a factor of 20.

Work will start with unit 1, because unlike unit 2 and 3 its containment vessel is assumed to be intact. Unit 2 and 3 are at atmospheric pressure. If they can’t maintain steam pressure they may also not hold water once they’re flooded. Also, because of a damaged torus (pressure suppression chamber), a lot more radioactivity has been leaking from unit 2 than from unit 1 and 3. That makes unit 1 by far the best candidate for trying out ideas on how to regain control and limiting further damage to the environment. However, there is no guarantee that, even if everything were to go perfectly on unit 1, any of the lessons learnt could be applied to the other units, since they may be too badly damaged to be repaired this way. The worst “patient” probably will be unit 2, which seemed to be leaking the most water. It isn’t clear how TEPCO is planning to deal with the leaking containments or the damaged torus. One approach might be to pump leaking water from the basement of the building back into the cooling system. TEPCO estimates 6 to 9 months for its “cold shutdown” plan.

Fallout prediction system went blind

Meanwhile it was reported that two systems meant to collect data from nuclear reactors and make predictions for nuclear fallout in Japan have failed to perform as intended. The Emergency Response Support System (ERSS) was supposed feed data from reactors into the System for Prediction of Envionmental Emergency Dose Information (SPEEDI). Both systems combined cost JPY 28 billion (about US$350 million), but ERSS failed along with everything else in Fukushima 1 when power was lost. It has yet to gather any data on the damaged units.

Radiation found on ocean floor

Caesium levels about 1000 times higher than normal have been found on the ocean floor 15-20 km from the Fukushima power plant, NHK reports:

The plant’s operator, Tokyo Electric Power Company, conducted its first contamination analysis of the seabed near the plant using samples from 2 points 20 to 30 meters deep on Friday.

Samples collected about 15 kilometers north of the plant contained 1,400 becquerels of cesium-137 per kilogram and 1,300 becquerels of cesium-134.

Samples taken around 20 kilometers south of the plant contained 1,200 becquerels each of cesium-137 and cesium-134 per kilogram.

The samples from the 2 points were also found to be contaminated with iodine-131.

TEPCO says it’s difficult to evaluate the readings as there are no official limits for these substances, but it will continue monitoring the radiation levels and their impact on seafood.

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Al Qaeda, the public domain franchise

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Millions of people will have cheered today when they heard the news of Osama bin Laden’s death. The leader of Al Qaeda had been on the FBI’s most wanted list since the 1998 US embassy bombings in Kenya and Tanzania and became even even more infamous after the 9/11 attacks.

Bin Ladin’s death is by no means “Mission accomplished” in the struggle against terrorism in countries around the world. More likely his death will make little difference.

For the last ten years he’s been little more than a figurehead for the movement he founded. “Al Qaeda in Iraq” picked up the brand name for its guaranteed headline value, but had different roots. Likewise the terrorist attacks in London and Madrid were organised independently. Bin Laden needed the Taliban and their paymasters at the ISI in Pakistan more than they needed him.

Other than its name recognition value, there was little in Bin Laden’s “brand” that couldn’t be found elsewhere by those who shared his world view and goals. Al Qaeda’s franchise manual is not proprietary information, it has been in the public domain for years.

To me the most hopeful news this year came not through the death of this evil man but through the courage of young men and women in Tunisia, Egypt and elsewhere, who boldly stood up against corrupt despots in their own countries. When young people in the Middle East have a stake in running their own countries, when they no longer feel powerless and abused then the likes of Al Qaeda will find it much harder to find new recruits amongst them.

Fukushima watch 2011-05-01

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The city of Koriyama in Fukushima prefecture, where top soil was removed from schools to reduce radiation exposure to children recently, is not only 50 km west of the Fukushima 1 nuclear power plant, it also lies in the heart of the central valley where most of the agricultural products of the otherwise mountainous region are grown.

Fukushima has already lost 90% of its fishing industry due to the tsunami. How much income will its farmers lose? Consumers can not be sure they will be safe if they eat crops produced in the region unless systematic testing takes place, but if high levels re found, farmers will demand compensation. How much will TEPCO have to pay and how much the government? In the 1950s nuclear power was sold to the public on the promise of being able to deliver electricity “too cheap to meter”. Now it could turn out as too expensive to measure.

Government advisor resigns in protest

Mr. Toshiso Kosako, a radiation export at the University of Tokyo has resigned as an advisor of the Japanese government, citing his opposition to raising permissible radiation exposure of school children. On April 19 the Ministry of Education and Scienced had announced a limit of 3.8 μSv/h (microsievert per hour), which is comparable to international maximum exposure rates of people working in nuclear power plants. Actually, 3.8 μSv/h times 24 hours times 365 days equals 33 mSv (millisievert), whereas in other countries the maximum permitted extra exposure on the job is 20 mSv, which comes on top of a natural radiation exposure of 2-3 mSv.

Radiation exposure of workers

Two workers at the Fukushima 1 nuclear power plant, employed by a sub-contractor of the power company, have been exposed to close to their maximum legal radiation dose:

The two workers have been exposed to 240.8 millisieverts and 226.6 millisieverts of radiation, respectively, when internal exposure is taken into account, among 21 workers exposed to over 100 millisieverts of external radiation since the crisis erupted following the magnitude 9 quake and tsunami, it said.

Under Japanese law, the Ministry of Health, Labor and Welfare has limited by an ordinance radiation exposure of each nuclear plant worker at 100 millisieverts a year in an emergency situation, but raised the limit to 250 millisieverts to cope with the Fukushima crisis on March 15.

The two were hospitalized for possible radiation burns to their feet after standing in water that contained radioactive materials 10,000 times the normal level while laying a cable underground at the troubled plant on March 24, the utility known as TEPCO said.

The limit for non-emergency work is 100 millisieverts over five years with no more than 50 per single year. These two workers received over 200 in a single month. The Ministry of Health and Welfare is planning to scrap the 50 mSv per year limit, leaving only the 100 mSv per five year limit in place for non-emergency workers. This is meant to make it possible to send workers from other reactors to Fukushima for cleanup work and still make it legal for them to absorb further radiation at regular work once they return.

Emergency power

TEPCO tested it’s mobile power generators at Higashidori nuclear power plant in Aomori prefecture on April 20 but revealed that the truck-mounted diesels had fuel for only 2 1/2 hours. If they have to provide power for longer they will need frequent refueling. In Fukushima 1 when the backup diesels failed it took about 9 days until grid power was restored inside the turbine halls to run electric pumps.

Radioactive contamination in unit 4 spent fuel pool

TEPCO has released updated numbers for radioactive contamination of the pool water in the spent fuel element pool of unit 4 of Fukushima 1. Here are the figures for 2011-04-29 (number for sample taken on 2011-04-13 in brackets):

  • Caesium 137 (half life: 30 years): 54,000 (was: 93,000 Bq/l)
  • Caesium 134 (half life: 2 years): 49,000 (was: 88,000 Bq/l)
  • Iodine 131 (half life: 8 days): 27,000 (was: 220,000 Bq/l)

Because 16 days have elapsed since the previous analysis, levels for iodine-131 should have halved twice (to about 55,000 Bq/l) while levels for both caesium isotopes should be virtually unchanged. Instead both caesium values dropped by more than 40% while Iodine is about 50% below the expected value. Where did the rest of the caesium and iodine go? There are several possible explanations.

Perhaps one of the analysises was simply wrong. That would not be out of the question, as TEPCO has had trouble with its figures before. More likely though, perhaps the water level was much lower on the first sample, meaning the current sample is diluted by a significant amount of added water (+72% water would explain the figures). That is to be hoped, because if the water level was in fact the same and the figures were correct then a lot of the pool water radioactivity would have had to escape into the atmosphere with steam or leaked with water to some other part of the reactor building.

Arnold Gundersen (YouTube, starting from 4:28) raised an interesting point about the isotope testing in the unit 4 pool: There’s too much iodine-131 for this to be from leaking fuel rods. The unit 4 reactor was shut down for maintenance on 2010-11-29, about 5 months ago. 151 days from 2010-11-29 to 2011-04-29 is close to 19 half lives for iodine-131, meaning only 2 millionths of the original iodine-131 levels should be left in the freshest nuclear waste in that pool, even less in older fuel rods. If 220,000 Bq/l came from atmospheric contamination (e.g. fallout from overheated unit 3 which is right next to it), then that is 220,000,000 Bq/m3 of water, left over after 4 half lives, so the original amount would have been 3,520,000,000. The pool is about 13m deep. To get it that radioactive, some 45,760,000,000 Bq/m2 had to land on the pool, which is a staggering amount.

Ubuntu 11.4, GA-H67MA-UD2H-B3, EarthWatts EA-380D, Centurion 5 II, 5K3000

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CoolerMaster Centurion 5 II

It’s been 2 months since I have written a blog post that wasn’t about the Tohoku earthquake and tsunami or the Fukushima 1 nuclear disaster, but today I am taking a break from those subjects. The reason is that I replaced my local Ubuntu server with newer hardware. The primary requirements were:

  • GNU/Linux (Ubuntu)
  • Reasonably low power usage
  • Large and very reliable storage
  • Affordability

I was considering boards ranging from the new AMD Zacate E-350 dual core to LGA-1155 (“Sandy Bridge”) boards with the Core i5 2500K. First Intel’s P67/H67 chip set problems and then the disaster in Japan prompted me to postpone the purchase.

Finally I picked the GigaByte GA-H67MA-UD2H-B3, a MicroATX board with 4 SIMM slots in conjunction with the Core i3 2100T, a 35W TDP part with dual cores and 4 threads. The boxed version of the Intel chip comes with a basic fan that didn’t sound too noisy to me. I installed two 4 GB DDR3 modules for a total of 8 GB of RAM, with two slots still available. When you install two memory modules on this board you should install them in memory slots of the same colour (either the blue or the white pair) to get the benefit of dual channel.

Gigabyte GA-H67MA-UD2H-B3

I chose a H67 board because of the lower power usage of the on-chip video and the 2100T has the lowest TDP of any Core 2000 chip. I don’t play games and my video needs are like for basic office PCs. Unlike P67 boards, H67 boards can not be overclocked. If you’re a gamer and care more about ultimate performance than power usage you would probably go for a P67 or Q67 board with an i5 2500K or i7 2600K with a discrete video card.

To minimize power use at the wall socket I picked an 80 Plus power supply (PSU), the Antec EarthWatts EA-380D Green. It meets the 80 Plus Bronze standard, which means it converts AC to DC with at least 82% efficiency at 20% load, at least 85% load at 50% load and at least 82% at full load. It’s the lowest capacity 80Plus PSU I could find here. 20% load for a 380W PSU is 76W. Since the standard does not specify the efficiency achieved below 20% of rated output and typically efficiency drops at the lower end, it doesn’t pay to pick an over-sized PSU.

Disk storage is provided by four Hitachi Deskstar 5K3000 drives of 2 TB each (HDS5C3020ALA632). These are SATA 6 Gbps drives, though that was not really a criterium (the 3 Gbps interface is still fast enough for any magnetic disks). I just happened to find them cheaper than the Samsung HD204UI that I was also considering and the drive had good reports from people who had used them for RAID5. The 2TB Deskstar is supposed to draw a little over 4W per drive at idle. I don’t use 7200 rpm drives in my office much because of heat, noise and power usage. Both types that I had considered have three platters of 667 GB each instead of 4 platters of 500 GB in older 2 TB drives: Fewer platters means less electricity and less heat. A three platter 2 TB drive should draw no more power than a 1.5 TB (3×500 TB) drive.

There are “enterprise class” drives designed specifically for RAID, but they cost two to three times more than desktop drives — so much for the “I” in RAID that is supposed to stand for “inexpensive”. These drives support a special error handling mode known as CCTL or TLER which some hardware RAID controllers and Windows require, but apparently the Linux software RAID driver copes fine with cheap desktop drives. The expensive drives also have better seek mechanisms to deal with vibration problems, but at least some of those vibration problems are worse with 7200 rpm drives than the 5400 rpm drives that I tend to buy.

Motherboard, PSU and 4 RAID drives in case

The case I picked was the CoolerMaster Centurion 5 II, which as you can see above is pretty large for a MicroATX board like the GA-H67MA-UD2H-B3, but I wanted enough space for at least 4 hard disks without crowding them in. Most cases that take only MicroATX boards and not full size ATX tend to have less space for internal hard disks or squeeze them in too tightly for good airflow. This case comes with two 12 cm fans and space to install three more 12 or 14 cm fans, not that I would need them. One of these fans blows cool air across the hard disks, which should minimize thermal problems even if you work those disks hard.

One slight complication was that the hard disks in the internal 3 1/4″ slots needed to be installed the opposite way most people expect: You have to take off both covers of the case, then connect power and SATA cables from the rear end (view to bottom of the motherboard) after sliding the drives in from the front side (view to top of motherboard). Once you do that you don’t even need L-shaped SATA cables. I could use the 4 SATA 6 Gbps cables that came with the GigaByte board. Most people expect to be able to install the hard disks just opening the front cover of the case and then run into trouble. It’s not a big deal once you figure it out, but quite irritating until then.

4 RAID drives in case

I installed Ubuntu 11.4, which has just been released, using the AMD64 alternate CD using a USB DVD drive. I configured the space for the /boot file system as a RAID1 with 4 drives and the / file system as a RAID6 with 4 drives with most of the space. Initially I had problems installing Grub as a boot loader after the manual partitioning, but the reason was that I needed to create a “bios_grub” partition on every drive before creating my boot and data RAID partitions.

RAID6 is like RAID5 but with two sets of parity data. Where the smallest RAID5 consists of three drives, a minimal RAID6 has four, with both providing two drives’ worth of net storage space. A degraded RAID6 (i.e. with one dead drive) effectively becomes a RAID5. That avoids nasty surprises that can happen with RAID5 when one of the other disks goes bad during a rebuild of a failed drive. If you order a spare when you purchase a RAID5 set and plan to keep the drive in a drawer until one of the others fails, you might as well go for a RAID6 to start with and gain the extra safety margin from day 1.

I had problems getting the on-board network port to work, so I first used a USB 2.0 network adapter and later installed an Intel Gigabit CT Desktop Adapter (EXPI9301CT). With two network interfaces you can use any Linux machine as a broadband router, there are various pre-configured packets for that.

While the RAID6 array was still syncing (writing checksums computed from data on two drives to two other drives) and therefore keeping all disks and partly the CPU busy the machine was drawing about 58W at the wall socket, as measured by my WattChecker Plus. Later, when the RAID had finished rebuilding and the server was just handling my spam feed traffic, power usage dropped to 52W at the wall socket. That’s about 450 kWh per year.

The total cost for the server with Core i3 2100T, 8 GB DDR3 RAM (1333), H67 MicroATX board, PCIe Ethernet card, 4 x 2 TB SATA drives, case and 380W PSU was just under 80,000 yen including tax, under US$1,000.