Re: MD/RAID time out writing superblock

Mark Lord
2009-08-31T23:45:38Z

Mark Lord wrote:
> Tejun Heo wrote:
>> Ric Wheeler wrote:
> ..
>>> The drive might take a longer time like this when doing error handling
>>> (sector remapping, etc), but then I would expect to see your remapped
>>> sector count grow.
>>
>> Yes, this is a possibility and according to the spec, libata EH should
>> be retrying flushes a few times before giving up but I'm not sure
>> whether keeping retrying for several minutes is a good idea either.
>> Is it?
> ..
>
> Libata will retry only when the FLUSH returns an error,
> and the next FLUSH will continue after the point where
> the first attempt failed.
>
> But if the drive can still auto-relocate sectors, then the
> first FLUSH won't actually fail.. it will simply take longer
> than normal.
>
> A couple of those, and we're into the tens of seconds range
> for time.
>
> Still, it would be good to actually produce an error like that
> to examine under controlled circumstances.
>
> Hmm.. I had a drive here that gave symptoms like that.
> Eventually, I discovered that drive had run out of relocatable
> sectors, too. Mmm.. I'll see if I can get it back (loaned it out)
> and perhaps we can recreate this specific scenario on it..
..

I checked today, and that drive is no longer available.

-ml