Dan Christensen wrote:

Bill Davidsen [off-list ref] writes:

  

quoted

Presumably something shows in the logs, that's the next place to look.
    

I believe my drives simply don't support adjusting the time it takes to
try to recover a read (CCTL).  Or did you mean the logs at the time of
failure?  If so, I posted those in the original message.

  

Those logs don't show any information useful to me which tells me how 
long md waited, and I'm not able to parse any of the res: information to 
gain clarity. It would be nice if someone can parse that, but I can't. 
On timeout an elapsed time output would be nice to indicate what the 
time limit is.

But I do have desktop drives in raid arrays, and they do spin down when 
not in use, and when I access the array after it's been unused I get a 
multi-second delay before my ls info comes back, so clearly there are 
some paths in the SATA handling which don't easily time out.

Have there been any kernel changes since 2.6.28 that might improve
reliability of my set-up?  It would be nice if md could be told to try
again before giving up on the drives.

  

Don't know, Neil might. I sure would like to see a timeout in ms in the 
/sys for the device and a flag for the array to not kick a drive for 
timeout until some number of consecutive timeouts have occurred. Note 
that I'm not suggesting some particular implementation, just some 
tunables. And if only one sector times out, a delayed reconstruct and 
rewrite might fix it. Again, a topic for discussion, not a "do thus" 
suggestion.

I would hope that a drive with multiple partitions would get the 
partitions kicked, not the whole drive at once. So one slow sector 
wouldn't take out multiple arrays.

Thanks for all of the help so far!

Dan

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-- 
Bill Davidsen [off-list ref]
  "We can't solve today's problems by using the same thinking we
   used in creating them." - Einstein