Long I/O pauses on same mass storage

[Mike Tancsa]

At 09:46 AM 5/12/2010, A. Wright wrote:
>While I will run some further tests here, I thought I would
>ask:
>
>         Is anyone else seeing poor disk I/O scheduling or locking
>         behaviour in 8.0?

Hi,
         On my backup server I am seeing somewhat better 
throughput/performance, at least with ZFS, but I have not done any 
rigorous comparisons.  Certainly nothing perceptible from userland


>         Is anyone aware of any of the filesytem changes that
>         have occurred since 7.2 that may explain this?

There are a lot, but then again the act of installing / upgrading 
could just mean you are now hitting bad sectors on the drive ?


>         Does anyone have any thoughts on how to conclusively
>         prove that the drive is at fault?  I have not seen any
>         errors logged to dmesg.

Start with smartmontools to ask your disk if it has logged any errors 
and check once a day or so to see if sectors are being remapped.

         ---Mike



>Thanks,
>Andrew.
>
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