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Oct 02, 2006

iAlertU + More

Cool - iAlertU is an alarm for your MacBook - it will even take pictures of the would be thief using the built in camera.

Amusing - RAID for the layman.

A fair proportion of the Top 100 International GDP's are now generated by Corporations. NZ is waaaay down the list at 81 below Nissan.

Be nice to your family or they'll have the final say on your tombstone.

Interesting insight into some of the design decisions surrounding the Nintendo Wii.

Also via ArsTechnica - Email is for old people. I read something about this regarding texting/IM culture in Japan and South Korea a few years ago - looks like the 'yoof' of the west are catching up.

View Flash media files using QuickTime player - Perian expands upon the number of media codecs the player will natively handle. This means you can view them in FrontRow too.

After a long posting-break GUIdebook is back with some historical scans and articles about the Apple Lisa (circa 1983).

Interesting - The Saga of Sagi Society. If its in Japan now I guess it will be in the rest of the world in a couple of years too. Bit depressing to think that technology is spawning new and innovative ways to blackmail people (granted the marks seem extraordinarily naive and/or stupid).

[/links/2006] | [permalink] | [2006.10.02-17:39.00]

Server Room Air Conditioning

Dealing with environmental alerts from your server room (it is monitored 24x7 right ?) is a major PITA. A properly designed server room should take into account proper cooling and venting. Unfortunately most people don't have the luxury of designing their server room from scratch and have to deal with adhoc cooling solutions.

We have a secondary server room that runs very very hot (30+ deg C) - luckily theres nothing super critical in there. Some digging has revealed that the 40+ devices in there pump out 70000 BTU. The BTU (British Thermal Unit - the wikipedia article is pretty fascinating - eg 12000 BTU is the amount of heat required to melt a ton of ice in 24hrs) seems to be the de facto standard for measuring server room cooling capability even though its been superceded in the metric world by the Joule.

At the moment the single ceiling mounted unit seems to be capable of handling 30000BTU and its running at 16 deg C. Running it this cold is pretty pointless as it will never achieve that temperature and trying to run at the units maximum capacity 24x7 is pretty unhealthy. We're looking at getting a portable unit in to handle an additional 20000 BTU - it won't handle the total load but it will take some of the strain off the primary unit.

To find out how many BTU's of cooling capacity are required:

* You need to calculate the size (assuming a 2m ceiling) of the room - length x width x 330BTU = heat from space

* You need to calculate the amount of heat generated by each device - total wattage (I guestimated 400w per device which is a little high) x 3.5 = heat from equipment

Then just add up the figures.

You can also figure in heat from windows, lights and people but unless its a big datacenter or the room faces the sun and has large windows its probably not going to be a huge amount - if you do want to work out the extra capacity to allow for these factors take a look at the calculations here.

Note that 1 Watt is 3.4 BTU when you check out cooling system specs - kW seems to be more common in NZ and the UK for cooling systems.

Thats the amount of cooling capacity your server room needs. Don't forget to allow for growth when you add gear and also redundancy in case you have a unit failure. In an old server room we had three wall mounted units - one big and two small; we could take a loss of one of the smaller ones but if the big unit went the temperature skyrocketed pretty quickly.

Also be sure to have good rack placement to provide airflow and ensure your racks have built-in fans to properly vent the heat away from the equipment.

[/tech/ultimate] | [permalink] | [2006.10.02-00:37.00]