Date: Tue, 24 Apr 2001 21:36:52 +0200 (CEST) From: Riccardo.Veraldi@fi.infn.it To: <freebsd-alpha@freebsd.org> Subject: machien check chapter 2, seeking for your opinions! Message-ID: <Pine.NEB.4.33.0104242123180.9229-100000@nikita.fi.infn.it>
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Hello folks! here is the chapter 2 of my misterious problem. 2 weeks ago I encountered this problem with My AlphaStation 255, FreeBSD 4.2-RELEASE: a massive use of programs like cp or tar (I/O bound) made the kernel crash with a machine check error. I Opened the AS deinstalled and reinstalled the SIMM modules, updated the SRM console cleanded all the inside parts carefully with compressed air etc... I do not know which of these operations was the correct one but after that I never had a problem with cp or tar, but I have been keeping trying some example which would make my AS crash again. I finally found a repetible experiment and operation which makes my AlphaStation crash every time. I am VERY INTERESTED to know your opinion to see if I can solve this problem. I created a 145600000 Bytes file called 'pp'. Then I kept using dd with different bs every time. I found the best disk performance for the disk is at bs=10485760 which gives me a I/O speed of 4.8MB/s. Now we are at the clue point... Anyway this following command makes my AlphaStation 255 crash every time I issue the command after a while (Seems when it reaches the end of the process because several seconds passes): dd bs=145600000 if=pp of=pp2 This command makes a machine check exception and I am back to the SRM console system crashes... this happens when the bs parameter is the same as the file size (in this case 145600000 Bytes). How come this happens ??? What could be the reason ?? How to fix it ?? Could it be a power supply problem really ? MY power supply is about 100Watts and the internal disk is a IBM DNES 18GB. A disk peak could suck enough watts so that the SIMM or CPU do not have enough watts for theirself making everyting crah ? My guess is the DISK is tooooo much low watts to give such a problem... Do you suggest me to use a smaller disk ??? I Am complitely OUT OF ANY IDEAS And really depressed at this point!! I Wanted to use my Alphastation as a Big Brother server but seems like I won't be able to! :( I am SUPER INTERESTED to know your valuable and precious opinions. Thanks Thousands in advance. Bye Rick To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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