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http://nemocam.phys.uwm.edu/img/video.asf
如果不能看的话,再试试这个页面,需要安装一个ActiveX控件的:
http://nemocam.phys.uwm.edu/img/image.cgi?next_file=main_fs.htm
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The two racks in the middle left with lots of blinking blue lights are the Einstein@Home servers. There are six 5U machines (each with 24 disks). These are (1) database server (2) project server (3) file server. All machines are duplicated in the second rack, to give us some hardware redundancy. At the base of the racks are the four UPS power supplies (each of the machines has four indepdendent power supplies, each connected to a different UPS).
I think that the webcam can only handle four connections at a time, so please disconnect after a couple of minutes of spying!
Cheers,
Bruce
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Einstein@Home has three large file servers. Each one is based on a dual-opteron supermicro motherboard, an AIC chassis with 24-hot-swap SATA disks, and an Areca 1170 RAID controller. We use 24 Western Digital 400GB RAID-edition disk drives (9.6 TB of raw disk space per file server) and run the RAID arrays in a RAID-6 configuration. This gives us 8.8 TB of usable storage space and two redundant disks per storage server.
Each AIC chassis contains six backplanes (each supporting four SATA disks). It turned out that AIC designed and manufactured these with an incorrect value of a critical resisitor. When all the drives were active, the drive voltage would sometimes dip below 4.75V and one of the drives would RESET.
The Areca controller would then think that the drive had been removed from the array and a new drive added. It would begin to rebuild the RAID array, a process that takes several hours and loads the server and disk drives.
In the middle of one of these rebuilds, a second drive reset itself. At that point we lost all redundancy and decided to shut down to reduce the risk of actual data loss.
We have now replaced the backplanes in the AIC cases with new ones, that contain the correct resistor value. I hope that from now on these critical file servers will be stable!
Cheers,
Bruce |
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发表于 2006-12-16 09:40:56
发表于 2006-12-16 11:12:19
发表于 2006-12-19 12:40:09