Re: [ceph-users] Running on disks that lose their head

[Loic Dachary <loic@dachary.org>]

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An anonymous kernel developer sends this link:

http://en.wikipedia.org/wiki/Error_recovery_control


On 06/11/2013 08:32, Loic Dachary wrote:
> Hi Ceph,
> 
> People from Western Digital suggested ways to better take advantage of the disk error reporting. They gave two examples that struck my imagination. First there are errors that look like the disk is dying ( read / write failures ) but it's only a transient problem and the driver should be able to make the difference by properly interpreting the available information. They said that the prolonged life you get if you don't decommission a disk that only has a transient error is significant. The second example is when one head out of ten fails : disks can keep working with the nine remaining heads. Losing 1/10 of the disk is likely to result in a full re-install of the Ceph osd. But, again, the disk could keep going after that, with 9/10 of its original capacity. And Ceph is good at handling osd failures.
> 
> All this is news to me and sounds really cool. But I'm sure there are people who already know about it and I'm eager to hear their opinion :-)
> 
> Cheers
> 
> 
> 
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> 

-- 
Loïc Dachary, Artisan Logiciel Libre


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