From: Bill D. <dav...@tm...> - 2008-12-17 20:43:54
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Redeeman wrote: > On Wed, 2008-12-10 at 19:11 -0500, Bill Davidsen wrote: > >> Justin Piszcz wrote: >> >>> Point of thread: Two problems, mentioned in detail below, NCQ in Linux >>> when used in a RAID configuration and two, something with how Linux >>> interacts with the drives causes lots of problems as when I run the WD >>> tools on the disks, they do not show any errors. >>> >>> If anyone has/would like me to run any debugging/patches/etc on this >>> system feel free to suggest/send me things to try out. After I put >>> the VR's in a test system, I left NCQ enabled and I made a 10 disk >>> raid5 to see how fast I could get it to fail, I ran bonnie++ shown >>> below as a disk benchmark/stress test: >>> >>> For the next test I will repeat this one but with NCQ disabled, having >>> NCQ enabled makes it fail very easily. Then I want to re-run the test >>> with RAID6. >>> >>> bonnie++ -d /r1/test -s 1000G -m p63 -n 16:100000:16:64 >>> >>> $ df -h >>> /dev/md3 2.5T 5.5M 2.5T 1% /r1 >>> >>> And the results? Two disk "failures" according to md/Linux within a >>> few hours as shown below: >>> >>> Note, the NCQ-related errors are what I talk about all of the time, if >>> you use >>> NCQ and Linux in a RAID environment with WD drives, well-- good luck. >>> >>> Two-disks failed out of the RAID5 and I currentlty cannot even 'see' >>> one of the drives with smartctl, will reboot the host and check sde >>> again. >>> >>> After a reboot, it comes up and has no errors, really makes one wonder >>> where/what the bugs is/are, there are two I can see: >>> 1. NCQ issue on at least WD drives in Linux in SW md/RAID >>> 2. Velociraptor/other disks reporting all kinds of sector errors etc, >>> but when you use the WD 11.x disk tools program and run all of their >>> tests it says the disks have no problems whatsoever! The smart >>> statistics do confirm this. Currently, TLER is on for all disks, for >>> the duration of these tests. >>> >> Just a few comments on this, I have several RAID arrays built on Seagate >> using NCQ, and yet to have a problem. I have NCQ on with my WD drives, >> non-RAID, and haven't had an issue with them either. The WDs run a lot >> cooler than the SG, but they are probably getting less use, as well. If >> the WD are still on sale after the holiday I may grab a few more and run >> RAID, by then I will have some small sense of trusting them. >> > Velociraptors, or which WD? > Calls itself "WDC WD10EACS-00D" in /sys if that helps. I could dig out the packing slip if it matters. Runs nicely so far, and if the SMART temperature probe is correct, very cool: /dev/sda: ST3750640AS: 43 C /dev/sdb: WDC WD10EACS-00D6B1: 31 C /dev/sdc: ST3750640AS: 44 C /dev/sdd: ST3750640AS: 46 C I don't totally trust the temps, there is a LOT of 18C air going into that box, because it has a lot coming out the back and side. -- Bill Davidsen <dav...@tm...> "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark |