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?