On Wed, Jun 20, 2007 at 11:21:42PM -0700, Keith Lofstrom wrote: > So, a request! Could some of you try adding the line: > > checksum: 1
After too little sleep, I woke from a nightmare about hard drives overheating. Checksum=1 /really/ thrashes the source and the target hard drive; huge numbers of head seeks for a long time. If either drive is poorly ventilated, something like this can heat the whole drive quite a bit. My Thinkpad laptop has the hard drive located well away from the flow of cooling air, and I observed that the "drive corner" of the machine was getting rather warm. I didn't think much of it. Then I noticed that I had a couple of unexplained system lockups on that machine since yesterday's checksum=1. I didn't think much of that, either. But put all that information together, and it made me realize that a hot hard drive may physically shrink or grow, and change mechanical tolerances. And that can mean that writes to the drive, after reading all that data, may have errors. If you have the smartd drive monitoring enabled, and properly equipped hard drives, you should do a "smartctl -a /dev/hdX" (where X is the drive) on your source and backup drives, paying particular attention to the "Temperature Celsius" line ( line 194 in my output ). Numbers like "100" and "253" are nonsense, numbers like "30 and 51" are accurate. This works for all my Seagate drives, not so good for the Maxtor drives or IBM or Toshiba drives. My Seagate laptop drive reached 53C, while the backup drive reached 44C. Most of my backup drives are well ventilated (in swap cages with individual fans ). So the backups should be safe, but I will pay close attention to the source drives. After I send this message, I will do an fsck on all the drives I thrashed yesterday, so I will be offline for a while. The bottom line: don't do "checksum: 1" tests on poorly ventilated drives until we have some more data about temperature consequences. Please do "checksum: 1" on well ventilated drives. Keith -- Keith Lofstrom [EMAIL PROTECTED] Voice (503)-520-1993 KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon" Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs _______________________________________________ Dirvish mailing list [email protected] http://www.dirvish.org/mailman/listinfo/dirvish
